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2001-07-24
Analytical expressions for the spin-spin local-field factor and the spin-antisymmetric exchange-correlation kernel of a two-dimensional electron gas
We present an analytical expression for the static many-body local field factor $G_{-}(q)$ of a homogeneous two-dimensional electron gas, which reproduces Diffusion Monte Carlo data and embodies the exact asymptotic behaviors at both small and large wave number $q$. This allows us to also provide a closed-form expressi...
0107501v1
2001-12-29
Longitudinal spin waves in a dilute Bose gas
We present a kinetic theory for a dilute noncondensed Bose gas of two-level atoms that predicts the transient spin segregation observed in a recent experiment. The underlying mechanism driving spin currents in the gas is due to a mean field effect arising from the quantum interference between the direct and exchange sc...
0112487v1
2003-08-29
Magnetic Order and Dynamics in Stripe-Ordered La2-xSrxNiO4
We have studied magnetic correlations in several compositions of stripe-ordered La2-xSrxNiO4. In this paper we show how polarized-neutron scattering has helped uncover important features of the magnetic ordering and spin dynamics. In particular, polarization analysis has enabled us (1) to characterize a spin reorientat...
0308631v1
2003-10-01
Rashba coupling in quantum dots: exact solution
We present an analytic solution to the problem of the Rashba spin-orbit coupling in semiconductor quantum dots. We calculate the exact energy spectrum, wave-functions, and spin--flip relaxation times. We discuss various effects inaccessible via perturbation theory. In particular, we find that the effective gyromagnetic...
0310024v2
2005-08-31
Order by disorder and gauge-like degeneracy in quantum pyrochlore antiferromagnet
The (three-dimensional) pyrochlore lattice antiferromagnet with Heisenberg spins of large spin length $S$ is a highly frustrated model with an macroscopic degeneracy of classical ground states. The zero-point energy of (harmonic order) spin wave fluctuations distinguishes a subset of these states. I derive an approxima...
0509005v1
2006-06-15
Optical spin pumping of modulation doped electrons probed by a two-color Kerr rotation technique
We report on optical spin pumping of modulation electrons in CdTe-based quantum wells with low intrinsic electron density (by 10^10 cm^{-2}). Under continuous wave excitation, we reach a steady state accumulated spin density of about 10^8 cm^{-2}. Using a two-color Hanle-MOKE technique, we find a spin relaxation time o...
0606419v1
2006-07-04
Scattering induced spin orientation and spin currents in gyrotropic structures
It is shown that additional contributions both to current-induced spin orientation and to the spin Hall effect arise in quantum wells due to gyrotropy of the structures. Microscopically, they are related to basic properties of gyrotropic systems, namely, linear in the wave vector terms in the matrix element of electron...
0607074v1
2006-07-08
Harper-Hofstadter problem for 2D electron gas with ${\bf k}$-linear Rashba spin-orbit coupling
The Harper-Hofstadter problem for two-dimensional electron gas with Rashba spin-orbit coupling subject to periodic potential and perpendicular magnetic field is studied analytically and numerically. The butterfly-like energy spectrum, spinor wave functions as well as the spin density and average spin polarization are c...
0607216v1
2007-03-08
Spin transverse force and quantum transverse transport
We present a brief review on spin transverse force, which exerts on the spin as the electron is moving in an electric field. This force, analogue to the Lorentz force on electron charge, is perpendicular to the electric field and spin current carried by the electron. The force stems from the spin-orbit coupling of elec...
0703196v1
2001-04-24
Extra Spin-Rotation Coupling Effect in a Radiating Kerr Space-time
Source-less wave equations are derived for massless scalar, neutrino and electromagnetic perturbations of a radiating Kerr space-time, and the Hawking radiation of massless particles with spin $s =0, 1/2$ and 1 in this geometry is investigated by using a method of the generalized tortoise coordinate transformation. An ...
0104074v1
2006-04-21
The Hyperfine Einstein-Infeld-Hoffmann Potential
We use recently developed effective field theory techniques to calculate the third order post-Newtonian correction to the spin-spin potential between two spinning objects. This correction represents the first contribution to the spin-spin interaction due to the non-linear nature of general relativity and will play an i...
0604099v1
1997-12-11
Greybody Factors for Black Holes in Four Dimensions: Particles with Spin
We compute the emission spectrum of minimally coupled particles with spin that are Hawking radiated from four dimensional black holes in string theory. For a range of the black hole parameters the result has a product structure that may be interpreted in terms of the respective right- and left-moving thermal correlatio...
9712118v1
2005-09-13
The continuous spin limit of higher spin field equations
We show that the Wigner equations describing the continuous spin representations can be obtained as a limit of massive higher-spin field equations. The limit involves a suitable scaling of the wave function, the mass going to zero and the spin to infinity with their product being fixed. The result allows to transform t...
0509092v2
2005-04-08
Spin as the Basis for Quantum Mechanics: A New Semiclassical Model for Electron Spin
A simple real-space model for the free-electron wavefunction with spin is proposed, based on coherent vortices on the scale of h/mc, rotating at mc^2/h. This reproduces the proper values for electron spin and magnetic moment. Transformation to a moving reference frame turns this into a wave with the de Broglie waveleng...
0504068v1
2007-06-13
Bispinor Formulation of Spin 3/2 Field Theory
In this paper, we investigate an alternative formulation for spin 3/2 field equation. First we will review equation of motion of Dirac and Maxwell, and then construct the equation for spin 3/2 in the similar fashion. Our method actually a generalization of relativistic equation of motion based on spin operator and Hami...
0706.1910v4
2007-12-07
Scattering of Spin-Zero and Spin-Half Particles in Momentum-Helicity Basis
Scattering of 2 particles of spin 0 and 1/2 is evaluated based on a basis constructed from the momentum and the helicity states (the momentum-helicity basis). This shortly called three-dimensional (3D) technique is a good alternative to the standard partial wave (PW) technique especially for higher energies, where PW c...
0712.1101v1
2008-11-11
Spin susceptibility, phase diagram, and quantum criticality in the electron-doped high Tc Superconductor Ba[Fe(1-x)Co(x)]2As2
We report a systematic investigation of Ba[Fe(1-x)Co(x)]2As2 based on transport and 75-As NMR measurements, and establish the electronic phase diagram. We demonstrate that doping progressively suppresses the uniform spin susceptibility and low frequency spin fluctuations. The optimum superconducting phase emerges at x_...
0811.1617v1
2008-11-13
Cooling into the Spin-Nematic State for a Spin-1 Bose gase in an optical lattice
The possibility of adiabatically cooling a spin-1 polar Bose gas to a spin-nematic phase is theoretically discussed. The relation between the order parameter of the final spin-nematic phase and the starting temperature of the spinor Bose gas is obtained both using the mean-field approach for the high temperature and sp...
0811.2054v1
2008-11-28
Effect of Nonlocal Spin-Transfer Torque on Current-Induced Magnetization Dynamics
Using the self-consistent model, we present nonlocal spin-transfer effects caused by the feedback between inhomogeneous magnetization and spin-transfer torque on the current-induced magnetization dynamics in nanomagnets. The nonlocal effects can substantially improve the coherence time of precession in nanomagnets and ...
0811.4649v1
2009-09-15
Critical current density for spin transfer torque switching with composite free layer structure
Critical current density of composite free layer (CFL) in magnetic tunneling junction is investigated. CFL consists of two exchange coupled ferromagnetic layers, where the coupling is parallel or anti-parallel. Instability condition of the CFL under the spin transfer torque, which is related with critical current densi...
0909.2711v1
2009-10-13
Boltzmann theory of magnetoresistance due to a spin spiral
We studied the magnetoresistance due to a spin spiral by solving the Boltzmann equation. The scattering rates of conduction electrons are calculated by using the non-perturbative wave function of the conduction electrons and the non-equilibrium distribution function is obtained by numerically solving the Boltzmann equa...
0910.2308v2
2010-08-06
Ferromagnetic phases in spin-Fermion systems
Spin-Fermion systems which obtain their magnetic properties from a system of localized magnetic moments being coupled to conducting electrons are considered. The dynamical degrees of freedom are spin-$s$ operators of localized spins and spin-1/2 Fermi operators of itinerant electrons. Renormalized spin-wave theory, whi...
1008.1148v1
2010-10-26
Spin Fidelity for Three-qubit Greenberger-Horne-Zeilinger and W States Under Lorentz Transformations
Constructing the reduced density matrix for a system of three massive spin$-\frac{1}{2}$ particles described by a wave packet with Gaussian momentum distribution and a spin part in the form of GHZ or W state, the fidelity for the spin part of the system is investigated from the viewpoint of moving observers in the jarg...
1010.5330v1
2012-03-27
Spin dynamics in the Kapitza-Dirac effect
Electron spin dynamics in Kapitza-Dirac scattering from a standing laser wave of high frequency and high intensity is studied. We develop a fully relativistic quantum theory of the electron motion based on the time-dependent Dirac equation. Distinct spin dynamics, with Rabi oscillations and complete spin-flip transitio...
1204.0239v2
2013-02-14
Spin-Hall Conductivity and Electric Polarization in Metallic Thin Films
We predict theoretically that, when a normal metallic thin film (without bulk spin-orbit coupling, such as Cu or Al) is sandwiched by two insulators, two prominent effects arise due to the interfacial spin-orbit coupling: a giant spin-Hall conductivity due to the surface scattering and a transverse electric polarizatio...
1302.3490v2
2013-06-25
Designing a Spin-Seebeck Diode
Using micromagnetic simulations, we have investigated spin dynamics in a spin-valve bi-layer in the presence of a thermal gradient. The direction and the intensity of the gradient allow to excite the spin wave modes of each layer selectively. This permits to synchronize the magnetization precession of the two layers an...
1306.5924v2
2014-01-27
Spin chains and classical strings in rotating Rindler-AdS space
In this paper, we study the spin chain and string excitation in the rotating Rindler-$AdS_3$ proposed in [12]. We obtain a one-parameter deformed $SL(2)$ spin chain at the fast spin limit. Two-spin GKP-like solutions are studied at short and long string limits. General ansatz for the giant magnons and the spiky strings...
1401.6915v1
2014-03-17
Massive twistor particle with spin generated by Souriau-Wess-Zumino term and its quantization
We present new model of D=4 relativistic massive particle with spin and we describe its quantization. The model is obtained by an extension of standard relativistic phase space description of massive spinless particle by adding new topological Souriau-Wess-Zumino term which depends on spin fourvector variable. We descr...
1403.4127v1
2019-11-05
Spin chains and classical strings in two parameters $q$-deformed AdS$_3\times$S$^3$
In this paper, we study the spin chain and string excitation in the two-parameters $q$-deformed AdS$_3\times$S$^3$ proposed by Hoare. We obtain the deformed spin chain model at the fast spin limit for choices of deformed parameters. General ansatz for giant magnons are studied in great detail and complicated dispersion...
1911.01567v1
2012-09-20
Quench dynamics in spin crossover induced by high pressure
In this paper we have studied analytically and numerically dynamics of spin crossover induced by time-dependent pressure. We show that quasi static pressure, with a slow dependence on time, yields a spin crossover leading to transition from the state of quantum system with high spin (HS) to the low spin (LS). However, ...
1209.4567v1
2018-02-21
Spin-fluctuations drive the inverse magnetocaloric effect in Mn5Si3
Inelastic neutron scattering measurements were performed on single crystals of the antiferromagnetic compound Mn5Si3 in order to investigate the relation between the spin dynamics and the magneto-thermodynamic properties. It is shown that among the two stable antiferromagnetic phases of this compound, the high temperat...
1802.07511v1
2019-02-11
Magnon excitations in $Cs_2CuAl_4O_8$ - a bond alternating S=1/2 spin chain with next nearest neighbor coupling
A recent density functional theory (DFT) based analysis, complemented with Quantum Monte Carlo calculations revealed a highly spin-frustrating nature of the one-dimensional spin-$\frac{1}{2}$ compound $Cs_2CuAl_4O_8$ that comprises of unique bond alternations and relatively strong next nearest neighbor interactions. Th...
1902.04008v1
2008-06-19
Anomalous Spin Response in Non-centrosymmetric Compounds
We examine static spin susceptibilities $\chi_{\alpha\beta}({\bf q})$ of spin components $S_{\alpha}$ and $S_{\beta}$ in the non-centrosymmetric tetragonal system. These show anomalous momentum dependences like $\chi_{xx}({\bf q})-\chi_{yy}({\bf q})\sim q_x^2-q_y^2$ and $\chi_{xy}({\bf q})+\chi_{yx}({\bf q})\sim q_x q_...
0806.3214v1
2019-12-09
Double-$Q$ Chiral Stripe in the $d$-$p$ Model with Strong Spin-Charge Coupling
We investigate the stability of multiple-$Q$ spiral states in $d$-$p$ electron systems with the strong spin-charge coupling. By using variational calculations on a square lattice, we find that the double-$Q$ state with the scalar chirality density wave, which has been studied in the weak spin-charge coupling regime, be...
1912.03906v1
2022-02-23
General Spin Sums in Quantum Field Theory
In Quantum Field Theory, scattering amplitudes are computed from propagators which, for internal lines, are built upon spin/polarization-sum relationships. In turn, these are normally constructed upon plane-wave solutions of the free field equations. A question that may now arise is whether such spin/polarization-sums ...
2203.04087v3
2022-05-30
Fledgling quantum spin Hall effect in pseudo gap phase of Bi2212
We study the emergence of the quantum spin Hall (QSH) states for the pseudo-gap (PG) phase of Bi2212 bilayer system, assumed to be D-density wave(DDW) ordered, starting with a strong Rashba spin-orbit coupling(SOC) armed, and the time reversal symmetry (TRS) complaint Bloch Hamiltonian. The presence of strong SOC gives...
2205.15010v1
2023-06-02
Chiral electrons and spin selectivity at chiral-achiral interfaces
Chiral molecules can selectively transport electrons of a particular spin orientation, yet the underlying mechanism remain poorly understood. Here, we present theoretical evidence that electrons propagating through chiral materials with screw symmetry exhibit chirality themselves and carry symmetry-induced pseudo-angul...
2306.01664v2
2023-07-31
Spin-frame field theory of a three-sublattice antiferromagnet
We present a nonlinear field theory of a three-sublattice hexagonal antiferromagnet. The order parameter is the spin frame, an orthogonal triplet of vectors related to sublattice magnetizations and spin chirality. The exchange energy, quadratic in spin-frame gradients, has three coupling constants, only two of which ma...
2307.16853v2
2023-08-31
Schwinger boson symmetric spin liquids of Shastry-Sutherland model
Motivated by recent experimental and numerical evidences of deconfined quantum critical point and quantum spin-liquid states in spin-$1/2$ Heisenberg model on Shastry-Sutherland lattice, we studied possible symmetric spin liquid states and their proximate ordered states under Schwinger boson formalism. We found a symme...
2308.16563v3
2023-12-13
Cubic action for Spinning Black Holes from massive higher-spin gauge symmetry
Scattering of two Kerr Black Holes emitting gravitational waves can be captured by an effective theory of a massive higher-spin field interacting with the gravitational field. While other compact objects should activate a multitude of non-minimal interactions it is the black holes that should be captured by the simples...
2312.08184v1
2012-12-10
An empirical study on a learning path on wave physics focused on energy
We describe an extracurricular learning path on waves focused on energy transfer. The advantages of introducing mechanical waves by using the Shive wave machine and laboratory activities are presented. Laboratories are realized by inquiry, i.e. students explore waves behavior in qualitative way, guess what can happen a...
1212.2174v1
2017-11-12
Double plasma resonance instability as a source of solar zebra emission
The double plasma resonance (DPR) instability plays a basic role in the generation of solar radio zebras. In the plasma, consisting of the loss-cone type distribution of hot electrons and much denser and colder background plasma, this instability generates the upper-hybrid waves, which are then transformed into the ele...
1711.04281v1
2005-01-26
High-field ESR studies of the quantum spin magnet CaCu2O3
We report an electron spin resonance (ESR) study of the s=1/2-Heisenberg pseudo-ladder magnet CaCu2O3 in pulsed magnetic fields up to 40 T. At sub-Terahertz frequencies we observe an ESR signal originating from a small amount of uncompensated spins residing presumably at the imperfections of the strongly antiferromagne...
0501647v3
2005-12-05
Twin spin/charge roton mode and superfluid density: primary determining factors of $T_{c}$ in high-$T_{c}$ superconductors observed by neutron, ARPES, and $μ$SR
In the quest for primary factors which determine the transition temperature $T_{c}$ of high-$T_{c}$ cuprate superconductors (HTSC), we develop a phenomenological picture combining experimental results from muon spin relaxation ($\mu$SR), neutron and Raman scattering, and angle-resolved photoemission (ARPES) measurement...
0512075v1
2007-05-16
Quantum spin liquid states in the two dimensional kagome antiferromagnets, ZnxCu4-x(OD)6Cl2
A three-dimensional system of interacting spins typically develops static long-range order when it is cooled. If the spins are quantum (S = 1/2), however, novel quantum paramagnetic states may appear. The most highly sought state among them is the resonating valence bond (RVB) state in which every pair of neighboring q...
0705.2279v1
2009-05-04
$T_1$- and $T_2$-spin relaxation time limitations of phosphorous donor electrons near crystalline silicon to silicon dioxide interface defects
A study of donor electron spins and spin--dependent electronic transitions involving phosphorous ($^{31}$P) atoms in proximity of the (111) oriented crystalline silicon (c-Si) to silicon dioxide (SiO$_{2}$) interface is presented for [$^{31}$P] = 10$^{15}$ $\mathrm{cm}^{-3}$ and [$^{31}$P] = 10$^{16}$ $\mathrm{cm}^{-3}...
0905.0416v1
2012-07-16
Decoherence mechanisms of 209Bi donor electron spins in isotopically pure 28Si
Bismuth (209Bi) is the deepest Group V donor in silicon and possesses the most extreme characteristics such as a 9/2 nuclear spin and a 1.5 GHz hyperfine coupling. These lead to several potential advantages for a Si:Bi donor electron spin qubit compared to the more common phosphorus donor. Previous studies on Si:Bi hav...
1207.3776v3
2014-08-27
Dynamics of a mesoscopic nuclear spin ensemble interacting with an optically driven electron spin
The ability to discriminate between simultaneously occurring noise sources in the local environment of semiconductor InGaAs quantum dots, such as electric and magnetic field fluctuations, is key to understanding their respective dynamics and their effect on quantum dot coherence properties. We present a discriminatory ...
1408.6437v2
2015-02-02
Two-axis spin squeezing in two cavities
Ultracold atoms in an ultrahigh-finesse optical cavity are a powerful platform to produce spin squeezing since photon of cavity mode can induce nonlinear spin-spin interaction and thus generate a one-axis twisting Hamiltonian $H_{\text{OAT}}=qJ_{x}^{2}$, whose corresponding maximal squeezing factor scales as $N^{-2/3}$...
1502.00470v1
2015-05-06
Bipolar polaron pair recombination in P3HT/PCBM solar cells
The unique properties of organic semiconductors make them versatile base materials for many applications ranging from light emitting diodes to transistors. The low spin-orbit coupling typical for carbon-based materials and the resulting long spin lifetimes give rise to a large influence of the electron spin on charge t...
1505.01411v1
2016-07-14
Spin dynamics of diamond nitrogen-vacancy centres at the ground state level anti-crossing and all-optical low frequency magnetic field sensing
We investigate the photo-induced spin dynamics of single nitrogen-vacancy (NV) centres in diamond near the electronic ground state level anti-crossing (GSLAC), which occurs at an axial magnetic field around 1024 G. Using optically detected magnetic resonance spectroscopy, we first find that the electron spin transition...
1607.04006v1
2017-08-09
Electrically driven electron spin resonance mediated by spin-valley-orbit coupling in a silicon quantum dot
The ability to manipulate electron spins with voltage-dependent electric fields is key to the operation of quantum spintronics devices, such as spin-based semiconductor qubits. A natural approach to electrical spin control exploits the spin-orbit coupling (SOC) inherently present in all materials. So far, this approach...
1708.02903v2
2018-05-22
FMR-related phenomena in spintronic devices
Spintronic devices, such as non-volatile magnetic random access memories and logic devices, have attracted considerable attention as potential candidates for future high efficient data storage and computing technology. In a heavy metal or other emerging material with strong spin-orbit coupling (SOC), the charge current...
1805.08496v1
2014-06-02
Knight shift and nuclear spin relaxation in Fe/n-GaAs heterostructures
We investigate the dynamically polarized nuclear-spin system in Fe/\emph{n}-GaAs heterostructures using the response of the electron-spin system to nuclear magnetic resonance (NMR) in lateral spin-valve devices. The hyperfine interaction is known to act more strongly on donor-bound electron states than on those in the ...
1406.0436v2
2019-02-04
Electron Spin Resonance of P Donors in Isotopically Purified Si Detected by Contactless Photoconductivity
Coherence times of electron spins bound to phosphorus donors have been measured, using a standard Hahn echo technique, to be up to 20 ms in isotopically pure silicon with [P]$ = 10^{14}$ cm$^{-3}$ and at temperatures $\leq 4 $K. Although such times are exceptionally long for electron spins in the solid state, they are ...
1902.01343v3
2019-06-10
Room Temperature Initialisation and Readout of Intrinsic Spin Defects in a Van der Waals Crystal
Optically addressable spins in widebandgap semiconductors have become one of the most prominent platforms for exploring fundamental quantum phenomena. While several candidates in 3D crystals including diamond and silicon carbide have been extensively studied, the identification of spindependent processes in atomically ...
1906.03774v1
2017-06-25
Robust electric dipole transition at microwave frequencies for nuclear spin qubits in silicon
The nuclear spin state of a phosphorus donor ($^{31}$P) in isotopically enriched silicon-28 is an excellent host to store quantum information in the solid state. The spin's insensitivity to electric fields yields a solid-state qubit with record coherence times, but also renders coupling to other quantum systems very ch...
1706.08095v2
2019-03-07
Readout of a dopant spin in the anisotropic quantum dot with a single magnetic ion
Owing to exchange interaction between the exciton and magnetic ion, a quantum dot embedding a single magnetic ion is a great platform for optical control of individual spin. In particular, a quantum dot provides strong and sharp optical transitions, which give experimental access to spin states of an individual magneti...
1903.02969v1
2019-05-31
Fingerprints of Kitaev physics in the magnetic excitations of honeycomb iridates
In the quest for realizations of quantum spin liquids, the exploration of Kitaev materials - spin-orbit entangled Mott insulators with strong bond-directional exchanges - has taken center stage. However, in these materials the local spin-orbital j=1/2 moments typically show long-range magnetic order at low temperature,...
1905.13590v1
2020-03-02
Cavity quantum electrodynamic readout of a solid-state spin sensor
Robust, high-fidelity readout is central to quantum device performance. Overcoming poor readout is an increasingly urgent challenge for devices based on solid-state spin defects, particularly given their rapid adoption in quantum sensing, quantum information, and tests of fundamental physics. Spin defects in solids com...
2003.01104v1
2021-02-17
Optically reconfigurable quantum spin-valley Hall effect of light in coupled nonlinear ring resonator lattice
Scattering immune propagation of light in topological photonic systems may revolutionarize the design of integrated photonic circuits for information processing and communications. In optics, various photonic topological circuits have been developed, which were based on classical emulation of either quantum spin Hall e...
2102.08750v1
2016-11-23
X-ray imaging of spin currents and magnetisation dynamics at the nanoscale
Understanding how spins move in time and space is the aim of both fundamental and applied research in modern magnetism. Over the past three decades, research in this field has led to technological advances that have had a major impact on our society, while improving the understanding of the fundamentals of spin physics...
1611.07691v2
2022-06-08
Coherent spin dynamics of rare-earth doped crystals in the high-cooperativity regime
Rare-earth doped crystals have long coherence times and the potential to provide quantum interfaces between microwave and optical photons. Such applications benefit from a high cooperativity between the spin ensemble and a microwave cavity -- this motivates an increase in the rare earth ion concentration which in turn ...
2206.04027v2
2022-06-28
Strong coupling between a photon and a hole spin in silicon
Spins in semiconductor quantum dots constitute a promising platform for scalable quantum information processing. Coupling them strongly to the photonic modes of superconducting microwave resonators would enable fast non-demolition readout and long-range, on-chip connectivity, well beyond nearest-neighbor quantum intera...
2206.14082v2
2022-09-06
Temperature- and field angular-dependent helical spin period characterized by magnetic dynamics in a chiral helimagnet $MnNb_3S_6$
The chiral magnets with topological spin textures provide a rare platform to explore topology and magnetism for potential application implementation. Here, we study the magnetic dynamics of several spin configurations on the monoaxial chiral magnetic crystal $MnNb_3S_6$ via broadband ferromagnetic resonance (FMR) techn...
2209.02266v1
2022-11-07
Room temperature charge-to-spin conversion from q-2DEG at SrTiO3-based interfaces
Interfacial two-dimensional electron gas (2DEG), especially the SrTiO3-based ones at the unexpected interface of insulators, have emerged to be a promising candidate for efficient charge-spin current interconversion. In this article, to gain insight into the mechanism of the charge-spin current interconversion at the o...
2211.03383v1
2023-01-27
Realization of valley-spin polarized current via parametric pump in monolayer $\rm MoS_2$
Monolayer $MoS_2$ is a typical valleytronic material with valley-spin locked valence bands. We numerically investigate the valley-spin polarized current in monolayer $\rm MoS_2$ via adiabatic electron pumping. By introducing an exchange field to break the energy degeneracy of monolayer $MoS_2$, the top of its valence b...
2301.11644v1
2023-04-25
Spin-liquid-like state in a square lattice antiferromagnet
Collective behavior of spins, frustration-induced strong quantum fluctuations and subtle interplay between competing degrees of freedom in quantum materials can lead to correlated quantum states with fractional excitations that are essential ingredients for establishing paradigmatic models and have immense potential fo...
2304.13116v1
2007-11-02
Electric-field controlled spin reversal in a quantum dot with ferromagnetic contacts
Manipulation of the spin-states of a quantum dot by purely electrical means is a highly desirable property of fundamental importance for the development of spintronic devices such as spin-filters, spin-transistors and single-spin memory as well as for solid-state qubits. An electrically gated quantum dot in the Coulomb...
0711.0320v1
2017-02-01
Coherent Rabi dynamics of a superradiant spin ensemble in a microwave cavity
We achieve the strong coupling regime between an ensemble of phosphorus donor spins in a highly enriched $^{28}$Si crystal and a 3D dielectric resonator. Spins were polarized beyond Boltzmann equilibrium using spin selective optical excitation of the no-phonon bound exciton transition resulting in $N$ = $3.6\cdot10^{13...
1702.00504v1
2006-10-17
QPOs in microquasars: the spin problem
In the Galactic microquasars with double peak kHz quasi-periodic oscillations (QPOs), the ratio of the two frequencies is 3:2. This supports the suggestion that double peak kHz QPOs are due to a non-linear resonance between two modes of accretion disk oscillations. For the microquasars with known mass, we briefly compa...
0610497v1
1999-07-13
Nonlinear Spin Dynamics in Ferromagnets with Electron-Nuclear Coupling
Nonlinear spin motion in ferromagnets is considered with nonlinearity due to three factors: (i) the sample is prepared in a strongly nonequilibrium state, so that evolution equations cannot be linearized as would be admissible for spin motion not too far from equilibrium, (ii) the system considered consists of interact...
9907188v1
2001-07-17
Cu Nuclear Quadrupole Resonance Study of the Spin-Peierls Compound Cu1-xMgxGeO3: A Possibility of Precursory Dimerization
We report on a zero-field 63Cu nuclear quadrupole resonance (NQR) study of nonmagnetic Mg impurity substituted Cu1-xMgxGeO3 (single crystals; the spin-Peierls transition temperature Tsp~14, 13.5, and 11 K for x=0, 0.0043, and 0.020) in a temperature range from 4.2 K to 250 K. We found that below T*~77 K, Cu NQR spectra...
0107353v1
2001-12-07
Time Scales of Phonon Induced Decoherence of Semiconductor Spin Qubits
Decoherence of a shallow donor electron spin in silicon caused by electron-lattice interaction is studied. We find that there are two time scales associated with the evolution of the electron spin density matrix: the fast but incomplete decay due to the interaction with non-resonant phonons followed by slow relaxation ...
0112135v1
2002-06-12
Spin-spin cross-relaxation in single-molecule magnets
It is shown that dipolar and weak superexchange interactions between the spin systems of single-molecule magnets (SMM) play an important role in the relaxation of magnetization. These interactions can reduce or increase resonant tunneling. The one-body tunnel picture of SMMs is not always sufficient to explain the meas...
0206195v1
2003-05-14
Orbital order in the low-dimensional quantum spin system TiOCl probed by ESR
We present electron spin resonance data of Ti$^{3+}$ (3$d^1$) ions in single crystals of the novel layered quantum spin magnet TiOCl. The analysis of the g tensor yields direct evidence that the d_{xy} orbital from the t_{2g} set is predominantly occupied and owing to the occurrence of orbital order a linear spin chain...
0305317v2
2003-07-28
Optical Detection of Single-Electron Spin Decoherence in a Quantum Dot
We propose a method based on optically detected magnetic resonance (ODMR) to measure the decoherence time $T_{2}$ of a single electron spin in a semiconductor quantum dot. The electron spin resonance (ESR) of a single excess electron on a quantum dot is probed by circularly polarized laser excitation. Due to Pauli bloc...
0307669v2
2003-09-19
Quantum Dissipative Dynamics of the Magnetic Resonance Force Microscope in the Single-Spin Detection Limit
We study a model of a magnetic resonance force microscope (MRFM) based on the cyclic adiabatic inversion technique as a high-resolution tool to detect single electron spins. We investigate the quantum dynamics of spin and cantilever in the presence of coupling to an environment. To obtain the reduced dynamics of the co...
0309456v1
2004-09-10
A study of the deep structure of the energy landscape of glassy polystyrene: the exponential distribution of the energy-barriers revealed by high-field Electron Spin Resonance spectroscopy
The reorientation of one small paramagnetic molecule (spin probe) in glassy polystyrene (PS) is studied by high-field Electron Spin Resonance spectroscopy at two different Larmor frequencies (190 and 285 GHz). The exponential distribution of the energy-barriers for the rotational motion of the spin probe is unambigousl...
0409258v2
2004-11-10
Dynamical nuclear polarization and nuclear magnetic fields in semiconductor nanostructures
We investigate the dynamic nuclear polarization from the hyperfine interaction between nonequilibrium electronic spins and nuclear spins coupled to them in semiconductor nanostructures. We derive the time and position dependence of the induced nuclear spin polarization and dipolar magnetic fields. In GaAs/AlGaAs parabo...
0411277v1
2004-11-24
Spin-charge mixing effects on resonant tunneling in a polarized Luttinger Liquid
We investigate spin-charge mixing effect on resonant tunneling in spin-polarized Tomonaga-Luttinger liquid with double impurities. The mixing arises from Fermi velocity difference between two spin species due to Zeeman effect. Zero bias conductance is calculated as a function of gate voltage $V_{\rm g}$, gate magnetic ...
0411600v3
2005-12-02
Electrically detected electron spin resonance in a high mobility silicon quantum well
The resistivity change due to electron spin resonance (ESR) absorption is investigated in a high-mobility two-dimensional electron system formed in a Si/SiGe heterostructure. Results for a specific Landau level configuration demonstrate that the primary cause of the ESR signal is a reduction of the spin polarization, n...
0512041v4
2006-02-06
Switching the sign of photon induced exchange interactions in semiconductor microcavities with finite quality factors
We investigate coupling of localized spins in a semiconductor quantum dot embedded in a microcavity with a finite quality factor. The lowest cavity mode and the quantum dot exciton are coupled forming a polariton, whereas excitons interact with localized spins via exchange. The finite quality of the cavity Q is incorpo...
0602122v1
2006-02-10
Theory of Electric Dipole Spin Resonance in a Parabolic Quantum Well
A theory of Electric Dipole Spin Resonance (EDSR), that is caused by various mechanisms of spin-orbit coupling, is developed as applied to free electrons in a parabolic quantum well. Choosing a parabolic shape of the well has allowed us to find explicit expressions for the EDSR intensity and its dependence on the magne...
0602264v1
2006-05-12
Comment on Frequency response and origin of the spin-1/2 photolumines-cence-detected magnetic resonance in a pi-conjugated polymer
In a recent paper Segal et al. [1] attempted to explain the dynamics of spin 1/2 photoluminescence detected magnetic resonance (PLDMR) in films of a pi-conjugated polymer, namely a soluble de-rivative of poly(phenylene-vinylene) [MEH-PPV] using a model (dubbed TPQ), in which the PLDMR is due to spin dependent triplet-p...
0605322v1
2006-09-01
Spin dynamics of $Yb Rh_2 Si_2$ observed by Electron Spin Resonance
Below the Kondo temperature $T_{\rm K}$ electron spin resonance (ESR) usually is not observable from the Kondo-ion itself because the characteristic spin fluctuation energy results in a huge width of the ESR line. The heavy fermion metal YbRh$_{2}$Si$_{2}$ seems to be an exceptional case where definite ESR spectra show...
0609020v1
2006-09-11
Current-driven ferromagnetic resonance, mechanical torques and rotary motion in magnetic nanostructures
We study theoretically the detection and possible utilization of electric current-induced mechanical torques in ferromagnetic-normal metal heterostructures that are generated by spin-flip scattering or the absorption of transverse spin currents by a ferromagnet. To this end, we analyze the DC voltage signals over a spi...
0609258v2
2006-10-31
Resonant magnetoresistance in organic spin-valves
We investigate theoretically the effects of surface states over the magnetoresistance of Ni-based organic spin-valves. In particular we perform {\it ab initio} electronic transport calculations for a benzene-thiolate molecule chemically attached to a Ni [001] surface and contacted either by Te to another Ni [001] surfa...
0610866v1
2006-11-21
Resonating Valence Bond States in 2 and 3D: Brief History and Recent Examples
Resonating Valence Bond states are quantum spin liquids, having low energy spin-half (spinon) or spin-1 excitations. Although spins are `disordered', they posses subtle topological orders and some times chiral orders. RVB states are easily appreciated and seem natural in the quantum fluctuation dominated 1D world. In 2...
0611553v1
2007-01-31
Nuclear Magnetic Resonance Study of Ultrananocrystalline Diamonds
We report on a nuclear magnetic resonance (NMR) study of ultrananocrystalline diamond (UNCD) materials produced by detonation technique. Analysis of the 13C and 1H NMR spectra, spin-spin and spin-lattice relaxation times in purified UNCD samples is presented. Our measurements show that UNCD particles consist of a diamo...
0701771v1
2007-08-02
Spin-Valley Kondo Effect in Multi-electron Silicon Quantum Dots
We study the spin-valley Kondo effect of a silicon quantum dot occupied by $% \mathcal{N}$ electrons, with $\mathcal{N}$ up to four. We show that the Kondo resonance appears in the $\mathcal{N}=1,2,3$ Coulomb blockade regimes, but not in the $\mathcal{N}=4$ one, in contrast to the spin-1/2 Kondo effect, which only occu...
0708.0408v1
2007-09-04
Chaotic dynamics of two 1/2 spin-qubit system in the optical cavity
Spin systems are one of the most promising candidates for quantum computation. At the same time control of a system's quantum state during time evolution is one of the actual problems. It is usually considered that to hold well-known resonance condition in magnetic resonance is sufficient to control spin system. But be...
0709.0496v1
2007-09-27
Spin-liquid dynamics of pyrochlore magnets Gd2Ti2O7 and Gd2Sn2O7
The spin-liquid phase of two highly frustrated pyrochlore magnets Gd2Ti2O7 and Gd2Sn2O7 is probed using electron spin resonance in the temperature range 1.3 - 30 K. The deviation of the absorption line from the paramagnetic position \nu =\gamma H observed in both compounds below the Curie-Weiss temperature \Theta_CW ~ ...
0709.4379v1
2008-04-29
Spin-magnetophonon level splitting in semimagnetic quantum wells
Spin-magnetophonon level splitting in a quantum well made of a semimagnetic wide gap semiconductor is considered. The semimagnetic semiconductors are characterized by a large effective $g$ factor. The resonance conditions $\hbar\omega_{\rm LO}=\mu_BgB$ for the spin flip between two Zeeman levels due to interaction with...
0804.4654v1
2008-09-17
Enhanced spin Hall effect by resonant skew scattering in orbital-selective Kondo effect
The enhanced spin Hall effect in Au metal due to the resonant skew scattering is studied with first-principles band structure calculations. Especially the gigantic spin Hall angle $\gamma_S \cong 0.1$ observed recently (T.Seki et al., Nature Materials {\bf 7}, 125 (2008)) is attributed to the orbital-dependent Kondo ef...
0809.2921v1
2008-10-06
Testing a possible W and Z structure at the LHC/CERN
One of the first channels to be experimentally analyzed at the LHC is $ p + p \longrightarrow l^+ + l ^- + X $. A resonance in this channel would be a clear indication of a new gauge neutral boson, as proposed in many extended models. In this paper we call attention to the possibility that the new resonance in this cha...
0810.1027v2
2008-12-12
Spin diffusion and magnetic eigenoscillations confined to single molecular layers in the organic conductors kappa-(BEDT-TTF)_2Cu[N(CN)_2X (X=Cl, Br)
The layered organic compounds, kappa-(BEDT-TTF)_2Cu[N(CN)_2X (X=Cl, Br) are metals at ambient temperatures. At low temperatures, the Cl compound is a weakly ferromagnetic Mott insulator while the isostructural Br compound is a superconductor. We find by conduction electron spin resonance (CESR) and antiferromagnetic re...
0812.2383v1
2009-01-09
Collective spin excitations in a quantum spin ladder probed by high-resolution Resonant Inelastic X-ray Scattering
We investigate magnetic excitations in the spin-ladder compound Sr$_{14}$Cu$_{24}$O$_{41}$ using high-resolution Cu $L_3$-edge Resonant Inelastic X-ray Scattering (RIXS). Our findings demonstrate that RIXS couples to collective spin excitations from a quantum spin-liquid ground state. In contrast to Inelastic Neutron S...
0901.1331v2
2009-04-09
Resonant tunneling-based spin ratchets
We outline a generic ratchet mechanism for creating directed spin-polarized currents in ac-driven double well or double dot structures by employing resonant spin transfer through the system engineered by local external magnetic fields. We show its applicability to semiconductor nanostructures by considering coherent tr...
0904.1518v1
2009-06-30
Cooling a magnetic resonance force microscope via the dynamical back-action of nuclear spins
We analyze the back-action influence of nuclear spins on the motion of the cantilever of a magnetic force resonance microscope. We calculate the contribution of nuclear spins to the damping and frequency shift of the cantilever. We show that, at the Rabi frequency, the energy exchange between the cantilever and the spi...
0906.5420v2