publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
|---|---|---|---|
2024-02-02 | Controllable frequency tunability and parabolic-like threshold current behavior in spin Hall nano-oscillators | We investigate the individual impacts of critical magnetodynamical
parameters-effective magnetization and magnetic damping-on the auto-oscillation
characteristics of nano-constriction-based Spin Hall Nano-Oscillators (SHNOs).
Our micromagnetic simulations unveil a distinctive non-monotonic relationship
between current ... | 2402.01570v1 |
2024-03-18 | Radiative loss and ion-neutral collisional effects in astrophysical plasmas | In this paper we study the role of radiative cooling in a two-fluid model
consisting of coupled neutrals and charged particles. We first analyze the
linearized two-fluid equations where we include radiative losses in the energy
equation for the charged particles. In a 1D geometry for parallel propagation
and in the lim... | 2403.11900v1 |
2001-01-12 | Spatial gradients in the cosmological constant | It is possible that there may be differences in the fundamental physical
parameters from one side of the observed universe to the other. I show that the
cosmological constant is likely to be the most sensitive of the physical
parameters to possible spatial variation, because a small variation in any of
the other parame... | 0101130v1 |
1999-01-22 | Longitudinal wavevector- and frequency-dependent dielectric constant of the TIP4P water model | A computer adapted theory for self-consistent calculations of the wavevector-
and frequency-dependent dielectric constant for interaction site models of
polar systems is proposed. A longitudinal component of the dielectric constant
is evaluated for the TIP4P water model in a very wide scale of wavenumbers and
frequenci... | 9901036v1 |
2010-07-05 | On the Karman constant | Numerous studies in the past 40 years have established that turbulent flow
fields are populated by transient coherent structures that represent patches of
fluids moving cohesively for significant distances before they are worn out by
momentum exchange with the surrounding fluid. Two particular well-documented
structure... | 1007.0605v1 |
2020-01-08 | Assessing different approaches to ab initio calculations of spin wave stiffness | Ab initio calculations of the spin wave stiffness constant $D$ for elemental
Fe and Ni performed by different groups in the past have led to values with a
considerable spread of 50-100 %. We present results for the stiffness constant
$D$ of Fe, Ni, and permalloy Fe$_{0.19}$Ni$_{0.81}$ obtained by three different
approa... | 2001.02558v2 |
2021-05-19 | Sound attenuation derived from quenched disorder in solids | In scattering experiments, the dynamical structure factor (DSF) characterizes
inter-particle correlations and their time evolution. We analytically evaluated
the DSF of disordered solids with disorder in the spring constant, by averaging
over quenched disorder in the values of lattice bond strength, along the
acoustic ... | 2105.09393v1 |
2022-05-17 | Acoustic gravitational interaction revised | In this paper, we deduce the expression of the gravito-acoustic force between
two oscillating bubbles using the hypothesis that this type of force is a force
of scattering-absorption of the energy of excitatory waves. The expression of
the gravito-acoustic force at resonance highlights the dependence of this force
on t... | 2206.00435v1 |
2022-07-27 | Determination of Thickness-dependent Damping Constant and Plasma Frequency for Ultrathin Ag and Au Films: Nanoscale Dielectric Function | There is an ever increasing interest in the development of plasmonic 2D
nanomaterials, with widespread applications in optoelectronics, high resolution
microscopy, imaging and sensing, among others. With the current ability of
ultrathin noble metal film deposition down to a few monolayers in thickness,
there is a need ... | 2207.13580v1 |
1999-11-03 | Tensor Microwave Anisotropies from a Stochastic Magnetic Field | We derive an expression for the angular power spectrum of cosmic microwave
background anisotropies due to gravity waves generated by a stochastic magnetic
field and compare the result with current observations; we take into account
the non-linear nature of the stress energy tensor of the magnetic field.
For almost sc... | 9911040v1 |
2002-07-15 | On the Structure of the Iron K-Edge | It is shown that the commonly held view of a sharp Fe K edge must be modified
if the decay pathways of the series of resonances converging to the K
thresholds are adequately taken into account. These resonances display damped
Lorentzian profiles of nearly constant widths that are smeared to impose
continuity across the... | 0207324v2 |
2006-12-15 | Damp Mergers: Recent Gaseous Mergers without Significant Globular Cluster Formation? | Here we test the idea that new globular clusters (GCs) are formed in the same
gaseous ("wet") mergers or interactions that give rise to the young stellar
populations seen in the central regions of many early-type galaxies. We compare
mean GC colors with the age of the central galaxy starburst. The red GC
subpopulation ... | 0612415v1 |
1998-02-24 | Resonant steps and spatiotemporal dynamics in the damped dc-driven Frenkel-Kontorova chain | Kink dynamics of the damped Frenkel-Kontorova (discrete sine-Gordon) chain
driven by a constant external force are investigated. Resonant steplike
transitions of the average velocity occur due to the competitions between the
moving kinks and their radiated phasonlike modes. A mean-field consideration is
introduced to g... | 9802251v1 |
1999-03-11 | Thermally activated escape rates of uniaxial spin systems with transverse field | Classical escape rates of uniaxial spin systems are characterized by a
prefactor differing from and much smaller than that of the particle problem,
since the maximum of the spin energy is attained everywhere on the line of
constant latitude: theta=const, 0 =< phi =< 2*pi. If a transverse field is
applied, a saddle poin... | 9903192v2 |
2006-11-18 | Distributions of switching times of single-domain particles using a time quantified Monte Carlo method | Using a time quantified Monte Carlo scheme we performed simulations of the
switching time distribution of single mono-domain particles in the
Stoner-Wohlfarth approximation. We considered uniaxial anisotropy and different
conditions for the external applied field. The results obtained show the
switching time distributi... | 0611494v2 |
2006-11-22 | Magnetization damping in a local-density approximation | The linear response of itinerant transition metal ferromagnets to transverse
magnetic fields is studied in a self-consistent adiabatic local-density
approximation. The susceptibility is calculated from a microscopic Hamiltonian,
including spin-conserving impurities, impurity induced spin-orbit interaction
and magnetic ... | 0611588v1 |
2004-01-13 | Highly Damped Quasinormal Modes of Kerr Black Holes: A Complete Numerical Investigation | We compute for the first time very highly damped quasinormal modes of the
(rotating) Kerr black hole. Our numerical technique is based on a decoupling of
the radial and angular equations, performed using a large-frequency expansion
for the angular separation constant_{s}A_{l m}. This allows us to go much
further in ove... | 0401052v1 |
1992-06-21 | Gauge Dependence of the Resummed Thermal Gluon Self Energy | The gauge dependence of the hot gluon self energy is examined in the context
of Pisarski's method for resumming hard thermal loops. Braaten and Pisarski
have used the Ward identities satisfied by the hard corrections to the n-point
functions to argue the gauge fixing independence of the leading order resummed
QCD plasm... | 9206239v1 |
1993-05-07 | Thermal quark production in pure glue and quark gluon plasmas | We calculate production rates for massless $(u,d)$ and massive $(s,c,b)$
quarks in pure glue and quark gluon plasmas to leading order in the strong
coupling constant $g$. The leading contribution comes from gluon decay into
$q\bar q$ pairs, using a thermal gluon propagator with finite thermal mass and
damping rate. The... | 9305227v1 |
2005-06-28 | Liouville Decoherence in a Model of Flavour Oscillations in the presence of Dark Energy | We study in some detail the master equation, and its solution in a simplified
case modelling flavour oscillations of a two-level system, stemming from the
Liouville-string approach to quantum space time foam. In this framework we
discuss the appearance of diffusion terms and decoherence due to the
interaction of low-en... | 0506242v1 |
2006-04-07 | Quasi-periodic attractors, Borel summability and the Bryuno condition for strongly dissipative systems | We consider a class of ordinary differential equations describing
one-dimensional analytic systems with a quasi-periodic forcing term and in the
presence of damping. In the limit of large damping, under some generic
non-degeneracy condition on the force, there are quasi-periodic solutions which
have the same frequency ... | 0604162v1 |
1998-02-27 | New collective mode due to collisional coupling | Starting from a nonmarkovian conserving relaxation time approximation for
collisions we derive coupled dispersion relations for asymmetric nuclear
matter. The isovector and isoscalar modes are coupled due to asymmetric nuclear
meanfield acting on neutrons and protons differently. A further coupling is
observed by colli... | 9802083v1 |
2000-08-14 | Design of a 3 GHz Accelerator Structure for the CLIC Test Facility (CTF 3) Drive Beam | For the CLIC two-beam scheme, a high-current, long-pulse drive beam is
required for RF power generation. Taking advantage of the 3 GHz klystrons
available at the LEP injector once LEP stops, a 180 MeV electron accelerator is
being constructed for a nominal beam current of 3.5 A and 1.5 microsecond pulse
length. The hig... | 0008052v1 |
2004-11-02 | Supersymmetric free-damped oscillators: Adaptive observer estimation of the Riccati parameter | A supersymmetric class of free damped oscillators with three parameters has
been obtained in 1998 by Rosu and Reyes through the factorization of the Newton
equation. The supplementary parameter is the integration constant of the
general Riccati solution. The estimation of the latter parameter is performed
here by emplo... | 0411019v2 |
2007-01-30 | Charge Fluctuation of Dust Grain and Its Impact on Dusty-Acoustic Wave Damping | We consider the influence of dust charge fluctuations on damping of the
dust-ion-acoustic waves. It is assumed that all grains have equal masses but
charges are not constant in time - they may fluctuate in time. The dust charges
are not really independent of the variations in the plasma potentials. All
modes will influ... | 0701336v1 |
2004-01-28 | Bloch Equations and Completely Positive Maps | The phenomenological dissipation of the Bloch equations is reexamined in the
context of completely positive maps. Such maps occur if the dissipation arises
from a reduction of a unitary evolution of a system coupled to a reservoir. In
such a case the reduced dynamics for the system alone will always yield
completely po... | 0401177v1 |
2006-01-10 | Quantum Brownian motion and the Third Law of thermodynamics | The quantum thermodynamic behavior of small systems is investigated in
presence of finite quantum dissipation. We consider the archetype cases of a
damped harmonic oscillator and a free quantum Brownian particle. A main finding
is that quantum dissipation helps to ensure the validity of the Third Law. For
the quantum o... | 0601056v1 |
2007-08-26 | Geodesic plasma flows instabilities of Riemann twisted solar loops | Riemann and sectional curvatures of magnetic twisted flux tubes in Riemannian
manifold are computed to investigate the stability of the plasma astrophysical
tubes. The geodesic equations are used to show that in the case of thick
magnetic tubes, the curvature of planar (Frenet torsion-free) tubes have the
effect ct of ... | 0708.3473v1 |
2009-01-28 | Location- and observation time-dependent quantum-tunneling | We investigate quantum tunneling in a translation invariant chain of
particles. The particles interact harmonically with their nearest neighbors,
except for one bond, which is anharmonic. It is described by a symmetric double
well potential. In the first step, we show how the anharmonic coordinate can be
separated from... | 0901.4518v1 |
2010-01-06 | Freezing of spin dynamics and omega/T scaling in underdoped cuprates | The memory function approach to spin dynamics in doped antiferromagnetic
insulator combined with the assumption of temperature independent static spin
correlations and constant collective mode damping leads to omega/T scaling in a
broad range. The theory involving a non universal scaling parameter is used to
analyze re... | 1001.0837v1 |
2010-02-02 | Inertial Oscillations of Pinned Dislocations | Dislocation pinning plays a vital role in the plastic behaviour of a
crystalline solid. Here we report the first observation of the damped
oscillations of a mobile dislocation after it gets pinned at an obstacle in the
presence of a constant static shear load. These oscillations are found to be
inertial, instead of for... | 1002.0422v1 |
2010-05-20 | Line Solutions for the Euler and Euler-Poisson Equations with Multiple Gamma Law | In this paper, we study the Euler and Euler-Poisson equations in $R^{N}$,
with multiple $\gamma$-law for pressure function: \begin{equation}
P(\rho)=e^{s}\sum_{j=1}^{m}\rho^{\gamma_{j}}, \end{equation} where all
$\gamma_{i+1}>\gamma_{i}\geq1$, is the constants. The analytical line solutions
are constructed for the syst... | 1005.3651v1 |
2010-07-12 | Ferromagnetic Excitations in La$_{0.82}$Sr$_{0.18}$CoO$_{3}$ Observed Using Neutron Inelastic Scattering | Polarized neutron inelastic scattering has been used to measure spin
excitations in ferromagnetic La$_{0.82}$Sr$_{0.18}$CoO$_{3}$. The magnon
spectrum of these spin excitations is well defined at low energies but becomes
heavily damped at higher energies, and can be modeled using a quadratic
dispersion. We determined a... | 1007.1919v1 |
2010-09-15 | A discontinuous Galerkin method for the Vlasov-Poisson system | A discontinuous Galerkin method for approximating the Vlasov-Poisson system
of equations describing the time evolution of a collisionless plasma is
proposed. The method is mass conservative and, in the case that piecewise
constant functions are used as a basis, the method preserves the positivity of
the electron distri... | 1009.3046v2 |
2010-10-03 | Measurement of damping and temperature: Precision bounds in Gaussian dissipative channels | We present a comprehensive analysis of the performance of different classes
of Gaussian states in the estimation of Gaussian phase-insensitive dissipative
channels. In particular, we investigate the optimal estimation of the damping
constant and reservoir temperature. We show that, for two-mode squeezed vacuum
probe st... | 1010.0442v1 |
2010-10-18 | K-shell photoionization of Na-like to Cl-like ions of Mg, Si, S, Ar, and Ca | We present $R$-matrix calculations of photoabsorption and photoionization
cross sections across the K-edge of Mg, Si, S, Ar, and Ca ions with more than
10 electrons. The calculations include the effects of radiative and Auger
damping by means of an optical potential. The wave functions are constructed
from single-elect... | 1010.3734v1 |
2010-10-19 | A possible signature of cosmic neutrino decoupling in the nHz region of the spectrum of primordial gravitational waves | In this paper we study the effect of cosmic neutrino decoupling on the
spectrum of cosmological gravitational waves (GWs). At temperatures T>>1 MeV,
neutrinos constitute a perfect fluid and do not hinder GW propagation, while
for T<<1 MeV they free-stream and have an effective viscosity that damps
cosmological GWs by a... | 1010.3849v2 |
2011-04-25 | Exactly Solvable Nonhomogeneous Burgers Equations with Variable Coefficients | We consider a nonhomogeneous Burgers equation with time variable
coefficients, and obtain an explicit solution of the general initial value
problem in terms of solution to a corresponding linear ODE. Special exact
solutions such as generalized shock and multi-shock solitary waves, triangular
wave, N-wave and rational t... | 1104.4717v1 |
2011-07-15 | K-shell photoionization of Nickel ions using R-matrix | We present R-matrix calculations of photoabsorption and photoionization cross
sections across the K edge of the Li-like to Ca-like ions stages of Ni.
Level-resolved, Breit-Pauli calculations were performed for the Li-like to
Na-like stages. Term-resolved calculations, which include the mass-velocity and
Darwin relativi... | 1107.3146v1 |
2011-12-21 | A numerical method for computing radially symmetric solutions of a dissipative nonlinear modified Klein-Gordon equation | In this paper we develop a finite-difference scheme to approximate radially
symmetric solutions of the initial-value problem with smooth initial conditions
in an open sphere around the origin, where the internal and external damping
coefficients are constant, and the nonlinear term follows a power law. We prove
that ou... | 1112.4921v1 |
2012-02-25 | Fractional Order Phase Shaper Design with Routh's Criterion for Iso-damped Control System | Phase curve of an open loop system is flat in nature if the derivative of
phase with respect to frequency is zero. With a flat phase curve, the
corresponding closed-loop system exhibits an iso-damped property i.e. maintains
constant overshoot with the change of gain and with other parametric
variations. In recent past ... | 1202.5667v1 |
2012-07-18 | Attractiveness of periodic orbits in parametrically forced systemswith time-increasing friction | We consider dissipative one-dimensional systems subject to a periodic force
and study numerically how a time-varying friction affects the dynamics. As a
model system, particularly suited for numerical analysis, we investigate the
driven cubic oscillator in the presence of friction. We find that, if the
damping coeffici... | 1207.4319v1 |
2012-07-19 | Acoustic damping and dispersion in vitreous germanium oxide | New Brillouin scattering measurements of velocity and attenuation of sound in
the hypersonic regime are presented. The data are analyzed together with the
literature results at sonic and ultrasonic frequencies. As usual, thermally
activated relaxation of structural entities describes the attenuation at sonic
and ultras... | 1207.4582v1 |
2012-08-21 | Brownian transport in corrugated channels with inertia | The transport of suspended Brownian particles dc-driven along corrugated
narrow channels is numerically investigated in the regime of finite damping. We
show that inertial corrections cannot be neglected as long as the width of the
channel bottlenecks is smaller than an appropriate particle diffusion length,
which depe... | 1208.4401v2 |
2012-09-26 | Damping of giant dipole resonance in highly excited nuclei | The giant dipole resonance's (GDR) width and shape at finite temperature and
angular momentum are described within the phonon damping model (PDM), which
predicts an overall increase in the GDR's total width at low and moderate
temperature T, and its saturation at high T. At T< 1 MeV the GDR width remains
nearly constan... | 1209.5820v2 |
2012-10-12 | Threshold current for switching of a perpendicular magnetic layer induced by spin Hall effect | We theoretically investigate the switching of a perpendicular magnetic layer
by in-plane charge current due to the spin Hall effect. We find that, in the
high damping regime, the threshold switching current is independent of the
damping constant, and is almost linearly proportional to both effective
perpendicular magne... | 1210.3442v2 |
2012-10-15 | Symmetries of the quantum damped harmonic oscillator | For the non-conservative Caldirola-Kanai system, describing a quantum damped
harmonic oscillator, a couple of constant-of-motion operators generating the
Heisenberg-Weyl algebra can be found. The inclusion of the standard time
evolution generator (which is not a symmetry) as a symmetry in this algebra, in
a unitary man... | 1210.4058v1 |
2013-01-23 | Characterization of magnetostatic surface spin waves in magnetic thin films: evaluation for microelectronic applications | The authors have investigated the possibility of utilizing spin waves for
inter- and intra-chip communications, and as logic elements using both
simulations and experimental techniques. Through simulations it has been shown
that the decay lengths of magnetostatic spin waves are affected most by the
damping parameter, a... | 1301.5395v1 |
2013-04-15 | Energy dissipation in DC-field driven electron lattice coupled to fermion baths | Electron transport in electric-field-driven tight-binding lattice coupled to
fermion baths is comprehensively studied. We reformulate the problem by using
the scattering state method within the Coulomb gauge. Calculations show that
the formulation justifies direct access to the steady-state bypassing the
time-transient... | 1304.4269v1 |
2013-05-07 | Micromagnetic modelling of anisotropic damping in ferromagnet | We report a numerical implementation of the Landau-Lifshitz-Baryakhtar
theory, which dictates that the micromagnetic relaxation term obeys the
symmetry of the magnetic crystal, i. e. replacing the single intrinsic damping
constant with a tensor of corresponding symmetry. The effect of anisotropic
relaxation is studied ... | 1305.1641v2 |
2013-07-14 | Asteroseismic effects in close binary stars | Turbulent processes in the convective envelopes of the sun and stars have
been shown to be a source of internal acoustic excitations. In single stars,
acoustic waves having frequencies below a certain cutoff frequency propagate
nearly adiabatically and are effectively trapped below the photosphere where
they are intern... | 1307.3709v1 |
2013-07-31 | Dynamics of ions in the selectivity filter of the KcsA channel: Towards a coupled Brownian particle description | The statistical and dynamical properties of ions in the selectivity filter of
the KcsA ion channel are considered on the basis of molecular dynamics (MD)
simulations of the KcsA protein embedded in a lipid membrane surrounded by an
ionic solution. A new approach to the derivation of a Brownian dynamics (BD)
model of io... | 1307.8298v1 |
2013-10-09 | Improved Coincident and Coherent Detection Statistics for Searches for Gravitational Wave Ringdown Signals | We study an improved method for detecting gravitational wave (GW) signals
from perturbed black holes by earth-based detectors in the quest for searching
for intermediate-mass black holes (IMBHs). Such signals, called ringdowns, are
damped sinusoids whose frequency and damping constant can be used to measure a
black hol... | 1310.2341v2 |
2014-04-25 | Nonlinear and Linear Timescales near Kinetic Scales in Solar Wind Turbulence | The application of linear kinetic treatments to plasma waves, damping, and
instability requires favorable inequalities between the associated linear
timescales and timescales for nonlinear (e.g., turbulence) evolution. In the
solar wind these two types of timescales may be directly compared using
standard Kolmogorov-st... | 1404.6569v1 |
2014-09-01 | Damping of Bloch oscillations: Variational solutions of the Boltzmann equation beyond linear response | Variational solutions of the Boltzmann equation usually rely on the concept
of linear response. We extend the variational approach for tight-binding models
at high entropies to a regime far beyond linear response. We analyze both
weakly interacting fermions and incoherent bosons on a lattice. We consider a
case where t... | 1409.0560v2 |
2014-12-12 | Spin waves in micro-structured yttrium iron garnet nanometer-thick films | We investigated the spin-wave propagation in a micro-structured yttrium iron
garnet waveguide of $40$ nm thickness. Utilizing spatially-resolved Brillouin
light scattering microscopy, an exponential decay of the spin-wave amplitude of
$(10.06 \pm 0.83)$ $\mu$m was observed. This leads to an estimated Gilbert
damping co... | 1412.4032v1 |
2015-10-01 | Production of charged Higgs boson pairs in the $pp \to ppH^{+}H^{-}$ reaction at the LHC and FCC | We present differential cross sections for the $pp \to ppH^{+}H^{-}$ reaction
via photon-photon fusion with exact kinematics. We show predictions for
$\sqrt{s}$ = 14 TeV (LHC) and at the Future Circular Collider (FCC) for
$\sqrt{s}$ = 100 TeV. The integrated cross section for $\sqrt{s}$ = 14~TeV
(LHC) is about 0.1~fb a... | 1510.00171v1 |
2015-10-15 | On the global existence and blowup of smooth solutions of 3-D compressible Euler equations with time-depending damping | In this paper, we are concerned with the global existence and blowup of
smooth solutions of the 3-D compressible Euler equation with time-depending
damping $$
\partial_t\rho+\operatorname{div}(\rho u)=0, \quad
\partial_t(\rho u)+\operatorname{div}\left(\rho u\otimes
u+p\,I_{3}\right)=-\,\frac{\mu}{(1+t)^{\lambda}... | 1510.04613v1 |
2015-12-16 | Back to Maupertuis' least action principle for dissipative systems: not all motions in Nature are most energy economical | It is shown that an oldest form of variational calculus of mechanics, the
Maupertuis least action principle, can be used as a simple and powerful
approach for the formulation of the variational principle for damped motions,
allowing a simple derivation of the Lagrangian mechanics for any dissipative
systems and an a co... | 1512.05339v1 |
2016-05-01 | Optical trapping by Laguerre-Gaussian beams: Symmetries, stability and equilibria | We use the T-matrix formalism in combination with the method of far-field
matching to evaluate the optical force exerted by Laguerre-Gaussian (LG) light
beams on a spherical (Mie) particle. For both non-vortex and optical vortex LG
beams, the theoretical results are used to analyze the optical-force-induced
dynamics of... | 1605.00243v2 |
2016-05-05 | Relaxation of Ferroelectric States in 2D Distributions of quantum Dots:EELS Simulation | The relaxation time of collective electronic states in a 2D distribution of
quantum dots is investigated theoretically by simulating EELS experiments. From
the numerical calculation of the probability of energy loss of an electron
beam, traveling parallel to the distribution, it is possible to estimate the
damping time... | 1605.01642v1 |
2016-07-27 | Linear and nonlinear viscoelastic arterial wall models: application on animals | This work deals with the viscoelasticity of the arterial wall and its
influence on the pulse waves. We describe the viscoelasticity by a non-linear
Kelvin-Voigt model in which the coefficients are fitted using experimental time
series of pressure and radius measured on a sheep's arterial network. We
obtained a good agr... | 1607.07973v1 |
2016-08-19 | Cooling a harmonic oscillator by optomechanical modification of its bath | Optomechanical systems show tremendous promise for high sensitivity sensing
of forces and modification of mechanical properties via light. For example,
similar to neutral atoms and trapped ions, laser cooling of mechanical motion
by radiation pressure can take single mechanical modes to their ground state.
Conventional... | 1608.05717v1 |
2016-09-30 | Origin of the effective mobility in non-linear active micro-rheology | The distinction between the damping coefficient and the effective non-linear
mobility of driven particles in active micro-rheology of supercooled liquids is
explained in terms of individual and collective dynamics. The effective
mobility arises as a collective effect which gives insight into the energy
landscape of the... | 1609.09853v1 |
2016-10-16 | Pulse-noise approach for classical spin systems | For systems of classical spins interacting with the bath via damping and
thermal noise, the approach is suggested to replace the white noise by a pulse
noise acting at regular time intervals $\Delta t$, within which the system
evolves conservatively. The method is working well in the typical case of a
small dimensionle... | 1610.04914v2 |
2017-03-22 | New versions of Newton method: step-size choice, convergence domain and under-determined equations | Newton method is one of the most powerful methods for finding solutions of
nonlinear equations and for proving their existence. In its "pure" form it has
fast convergence near the solution, but small convergence domain. On the other
hand damped Newton method has slower convergence rate, but weaker conditions on
the ini... | 1703.07810v2 |
2017-05-21 | Plasmon modes in graphene-GaAs heterostructures | We investigate the plasmon dispersion relation and damping rate of collective
excitations in a double-layer system consisting of bilayer graphene and GaAs
quantum well, separated by a distance, at zero temperature with no interlayer
tunneling. We use the random-phase-approximation dielectric function and take
into acco... | 1705.07389v1 |
2017-06-05 | Consistent microscopic analysis of spin pumping effects | We present a consistent microscopic study of spin pumping effects for both
metallic and insulating ferromagnets. As for metallic case, we present a simple
quantum mechanical picture of the effect as due to the electron spin flip as a
result of a nonadiabatic (off-diagonal) spin gauge field. The effect of
interface spin... | 1706.01185v1 |
2017-08-02 | Global existence of solutions for semi-linear wave equation with scale-invariant damping and mass in exponentially weighted spaces | In this paper we consider the following Cauchy problem for the semi-linear
wave equation with scale-invariant dissipation and mass and power
non-linearity: \begin{align}\label{CP abstract} \begin{cases} u_{tt}-\Delta
u+\dfrac{\mu_1}{1+t} u_t+\dfrac{\mu_2^2}{(1+t)^2}u=|u|^p, \\ u(0,x)=u_0(x),
\,\, u_t(0,x)=u_1(x), \end{... | 1708.00738v1 |
2017-08-21 | Solar Line Asymmetries: Modelling the Effect of Granulation on the Solar Spectrum | A parametric model of granulation employing a small number of parameters was
developed. Synthetic spectra calculated using this model closely match observed
spectra and, in particular, reproduce the asymmetries observed in spectral
lines. Both the microturbulent motions and the large-scale flow velocity
decrease expone... | 1708.06408v1 |
2017-11-01 | Plasmon modes in bilayer-monolayer graphene heterostructures | We investigate the dispersion relation and damping of plasmon modes in a
bilayer-monolayer graphene heterostructure with carrier densities and at zero
temperature within the random-phase-approximation taking into account the
nonhomogeneity of the dielectric background of the system. We derive analytical
expressions for... | 1711.00334v1 |
2018-07-15 | Asymptotic profile of solutions for semilinear wave equations with structural damping | This paper is concerned with the initial value problem for semilinear wave
equation with structural damping $u_{tt}+(-\Delta)^{\sigma}u_t -\Delta u
=f(u)$, where $\sigma \in (0,\frac{1}{2})$ and $f(u) \sim |u|^p$ or $u
|u|^{p-1}$ with $p> 1 + {2}/(n - 2 \sigma)$. We first show the global existence
for initial data smal... | 1807.05509v3 |
2018-12-28 | Axion Misalignment Driven to the Bottom | Several theoretical motivations point to ultralight QCD axions with large
decay constants $f_a \simeq \mathcal{O}(10^{16}-10^{17})$ GeV, to which
experimental proposals are dedicated. This regime is known to face the problem
of overproduction of axion dark matter from the misalignment mechanism unless
the misalignment ... | 1812.11186v2 |
2019-04-09 | Ferromagnetic Resonance Studies of Strain tuned Bi:YIG Films | Bismuth-doped Yttrium iron garnet (Bi:YIG) thin films known for large
Magneto-optical activity with low losses still needs to get probed for its
magnetization dynamics. We demonstrate a controlled tuning of
magnetocrystalline anisotropy in Bi-doped Y_3 Fe_5 O_12 (Bi:YIG) films of high
crystalline quality using growth i... | 1904.04800v2 |
2019-04-25 | Low damping magnetic properties and perpendicular magnetic anisotropy with strong volume contribution in the Heusler alloy Fe1.5CoGe | We present a study of the dynamic magnetic properties of TiN-buffered
epitaxial thin films of the Heusler alloy Fe$_{1.5}$CoGe. Thickness series
annealed at different temperatures are prepared and the magnetic damping is
measured, a lowest value of $\alpha=2.18\times 10^{-3}$ is obtained. The
perpendicular magnetic ani... | 1904.11247v1 |
2019-04-26 | Terahertz spin dynamics driven by a field-derivative torque | Efficient manipulation of magnetization at ultrashort time scales is of
particular interest for future technology. Here, we numerically investigate the
influence of the so-called field-derivative torque, which was derived earlier
based on relativistic Dirac theory [Mondal et al., Phys. Rev. B 94, 144419
(2016)], on the... | 1904.11768v2 |
2019-05-30 | Predicting New Iron Garnet Thin Films with Perpendicular Magnetic Anisotropy | Perpendicular magnetic anisotropy (PMA) is a necessary condition for many
spintronic applications like spin-orbit torques switching, logic and memory
devices. An important class of magnetic insulators with low Gilbert damping at
room temperature are iron garnets, which only have a few PMA types such as
terbium and sama... | 1905.13042v1 |
2019-05-30 | Intrinsically Undamped Plasmon Modes in Narrow Electron Bands | Surface plasmons in 2-dimensional electron systems with narrow Bloch bands
feature an interesting regime in which Landau damping (dissipation via
electron-hole pair excitation) is completely quenched. This surprising behavior
is made possible by strong coupling in narrow-band systems characterized by
large values of th... | 1905.13088v2 |
2019-06-21 | Control of eigenfunctions on surfaces of variable curvature | We prove a microlocal lower bound on the mass of high energy eigenfunctions
of the Laplacian on compact surfaces of negative curvature, and more generally
on surfaces with Anosov geodesic flows. This implies controllability for the
Schr\"odinger equation by any nonempty open set, and shows that every
semiclassical meas... | 1906.08923v2 |
2019-07-17 | Inhomogeneous domain walls in spintronic nanowires | In case of a spin-polarized current, the magnetization dynamics in nanowires
are governed by the classical Landau-Lifschitz equation with Gilbert damping
term, augmented by a typically non-variational Slonczewski term. Taking axial
symmetry into account, we study the existence of domain wall type coherent
structure sol... | 1907.07470v2 |
2019-09-06 | The interplay of large two-magnon ferromagnetic resonance linewidths and low Gilbert damping in Heusler thin films | We report on broadband ferromagnetic resonance linewidth measurements
performed on epitaxial Heusler thin films. A large and anisotropic two-magnon
scattering linewidth broadening is observed for measurements with the
magnetization lying in the film plane, while linewidth measurements with the
magnetization saturated p... | 1909.02738v2 |
2019-12-10 | Stability of traveling waves in a driven Frenkel-Kontorova model | In this work we revisit a classical problem of traveling waves in a damped
Frenkel-Kontorova lattice driven by a constant external force. We compute these
solutions as fixed points of a nonlinear map and obtain the corresponding
kinetic relation between the driving force and the velocity of the wave for
different value... | 1912.05052v2 |
2020-05-20 | Dynamic Peach-Koehler self-force, inertia, and radiation damping of a regularized dislocation | The elastodynamic Peach-Koehler force is computed for a fully-regularized
straight dislocation with isotropic core in continuum isotropic elastic
elasticity, in compact forms involving partial mass or impulsion functions
relative to shear and compressional waves. The force accounts for both dynamic
radiation damping an... | 2005.12704v2 |
2020-06-29 | Collective excitations in spin-polarized bilayer graphene | We calculate the plasmon frequency and damping rate of plasma oscillations in
a spin-polarized BLG system. Using the long wavelength approximation for
dynamical dielectric function, we obtain an analytical expression for plasmon
frequency showing that the degree of spin polarization P has negligible effect
on the long ... | 2006.16042v2 |
2020-08-14 | Testing Dissipative Collapse Models with a Levitated Micromagnet | We present experimental tests of dissipative extensions of spontaneous wave
function collapse models based on a levitated micromagnet with ultralow
dissipation. The spherical micromagnet, with radius $R=27$ $\mu$m, is levitated
by Meissner effect in a lead trap at $4.2$ K and its motion is detected by a
SQUID. We perfo... | 2008.06245v2 |
2020-08-14 | Large enhancement of spin pumping due to the surface bound states in normal metal/superconductor structures | We show that the spin pumping from ferromagnetic insulator into the adjacent
metallic spin sink can be strongly stimulated by the superconducting
correlations.
The key physical mechanism responsible for this effect is the presence of
quasiparticle surface states at the ferromagnetic insulator/superconductor
interface... | 2008.06253v1 |
2020-10-28 | Spin-valley collective modes of the electron liquid in graphene | We develop the theory of collective modes supported by a Fermi liquid of
electrons in pristine graphene. Under reasonable assumptions regarding the
electron-electron interaction, all the modes but the plasmon are over-damped.
In addition to the $SU(2)$ symmetric spin mode, these include also the valley
imbalance modes ... | 2010.15154v2 |
2020-11-14 | Oscillating charge currents of one-dimensional Hubbard model in an electric field | The time evolution properties of charge current for the one-dimensional
Hubbard model in an electric field have been studied in a rigorous manner. We
find that there is a complete and orthonormal set of time-evolution states for
which the charge current can only keep zero or oscillate constantly, differing
from the pos... | 2011.07220v2 |
2021-01-15 | Efficient Spin-Orbit Torque Generation in Semiconducting WTe2 with Hopping Transport | Spin-orbit torques (SOTs) from transition metal dichalcogenides systems
(TMDs) in conjunction with ferromagnetic materials are recently attractive in
spintronics for their versatile features. However, most of the previously
studied crystalline TMDs are prepared by mechanical exfoliation, which limits
their potentials f... | 2101.06047v1 |
2021-03-13 | Dissipative structures in a parametrically driven dissipative lattice: chimera, localized disorder, continuous-wave, and staggered state | Discrete dissipative coupled systems exhibit complex behavior such as chaos,
spatiotemporal intermittence, chimera among others. We construct and
investigate chimera states, in the form of confined stationary and dynamical
states in a chain of parametrically driven sites with onsite damping and cubic
nonlinearity. The ... | 2103.07748v1 |
2021-05-31 | Machine-Learning Non-Conservative Dynamics for New-Physics Detection | Energy conservation is a basic physics principle, the breakdown of which
often implies new physics. This paper presents a method for data-driven "new
physics" discovery. Specifically, given a trajectory governed by unknown
forces, our Neural New-Physics Detector (NNPhD) aims to detect new physics by
decomposing the for... | 2106.00026v2 |
2021-07-29 | $n$-dimensional PDM-damped harmonic oscillators: Linearizability, and exact solvability | We consider position-dependent mass (PDM) Lagrangians/Hamiltonians in their
standard textbook form, where the long-standing \emph{gain-loss balance}
between the kinetic and potential energies is kept intact to allow conservation
of total energy (i.e., $L=T-V$, $H=T+V$, and $dH/dt=dE/dt=0$). Under such
standard settings... | 2107.14617v1 |
2021-11-16 | Ultrathin ferrimagnetic GdFeCo films with very low damping | Ferromagnetic materials dominate as the magnetically active element in
spintronic devices, but come with drawbacks such as large stray fields, and low
operational frequencies. Compensated ferrimagnets provide an alternative as
they combine the ultrafast magnetization dynamics of antiferromagnets with a
ferromagnet-like... | 2111.08768v1 |
2021-11-30 | First and second order magnetic anisotropy and damping of europium iron garnet under high strain | Understanding and tailoring static and dynamic properties of magnetic
insulator thin films is important for spintronic device applications. Here, we
grow atomically flat epitaxial europium iron garnet (EuIG) thin films by pulsed
laser deposition on (111)-oriented garnet substrates with a range of lattice
parameters. By... | 2111.15142v1 |
2022-07-17 | Locational Aspect of Fast Frequency Reserves in Low-Inertia Systems -- Control Performance Analysis | This paper evaluates the frequency performance of an AC system when primary
frequency response is provided by inverter-based resources located at
remote-areas. Due to potentially larger wave propagation constants over longer
lines, fast active power response from inverter based resources may have a
negative impact on t... | 2207.08188v1 |
2022-08-17 | Linking fluctuation and dissipation in spatially extended out-of-equilibrium systems | For systems in equilibrium at a temperature $T$, thermal noise and energy
damping are related to $T$ through the fluctuation-dissipation theorem (FDT).
We study here an extension of the FDT to an out of equilibrium steady state: a
microcantilever subject to a constant heat flux. The resulting thermal profile
in this sp... | 2208.08356v2 |
2022-09-07 | Classical correlations for Generic States are Fragile under Decoherence | Quantum correlations typically decrease with increasing noise, although
classical correlators (CCors) may rise for a particular class of states with
noise. To analyse the behavior of classical correlation (CC) in the presence of
local noise, we scrutinize the set of classical correlators, axiomatic CC
measures like cla... | 2209.03334v1 |
2022-10-19 | Global well-posedness of the partially damped 2D MHD equations via a direct normal mode method for the anisotropic linear operator | We prove the global well-posedness of the 2D incompressible non-resistive MHD
equations with a velocity damping term near the non-zero constant background
magnetic field. To this end, we newly design a normal mode method of
effectively leveraging the anisotropy of the linear propagator that encodes
both the partially d... | 2210.10283v1 |
2022-11-07 | On Vacuum Free Boundary Problem of the Spherically Symmetric Euler Equations with Damping and Solid Core | In this paper, the global existence of smooth solution and the long-time
asymptotic stability of the equilibrium to vacuum free boundary problem of the
spherically symmetric Euler equations with damping and solid core have been
obtained for arbitrary finite positive gas constant $A$ in the state equation
$p=A \rho^\gam... | 2211.03347v2 |
2022-11-16 | Endemic Oscillations for SARS-CoV-2 Omicron -- A SIRS model analysis | The SIRS model with constant vaccination and immunity waning rates is well
known to show a transition from a disease-free to an endemic equilibrium as the
basic reproduction number $r_0$ is raised above threshold. It is shown that
this model maps to Hethcote's classic endemic model originally published in
1973. In this... | 2211.09005v2 |
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