publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
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2019-09-10 | Spin Pumping from Permalloy into Uncompensated Antiferromagnetic Co doped Zinc Oxide | Heterostructures of Co-doped ZnO and Permalloy were investigated for their
static and dynamic magnetic interaction. The highly Co-doped ZnO is
paramagentic at room temperature and becomes an uncompensated antiferromagnet
at low temperatures, showing a narrowly opened hysteresis and a vertical
exchange bias shift even i... | 1909.04362v3 |
2020-02-27 | Ultrafast magnetization dynamics in half-metallic Co$_2$FeAl Heusler alloy | We report on optically induced, ultrafast magnetization dynamics in the
Heusler alloy $\mathrm{Co_{2}FeAl}$, probed by time-resolved magneto-optical
Kerr effect. Experimental results are compared to results from electronic
structure theory and atomistic spin-dynamics simulations. Experimentally, we
find that the demagn... | 2002.12255v1 |
2020-06-05 | Controlling the nonlinear relaxation of quantized propagating magnons in nanodevices | Relaxation of linear magnetization dynamics is well described by the viscous
Gilbert damping processes. However, for strong excitations, nonlinear damping
processes such as the decay via magnon-magnon interactions emerge and trigger
additional relaxation channels. Here, we use space- and time-resolved
microfocused Bril... | 2006.03400v2 |
2021-05-16 | Anatomy of inertial magnons in ferromagnets | We analyze dispersion relations of magnons in ferromagnetic nanostructures
with uniaxial anisotropy taking into account inertial terms, i.e. magnetic
nutation. Inertial effects are parametrized by damping-independent parameter
$\beta$, which allows for an unambiguous discrimination of inertial effects
from Gilbert damp... | 2105.07376v1 |
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 |
2022-10-01 | Nonlinear features of the superconductor--ferromagnet--superconductor $\varphi_0$ Josephson junction in ferromagnetic resonance region | We demonstrate the manifestations of the nonlinear features in magnetic
dynamics and IV-characteristics of the $\varphi_0$ Josephson junction in the
ferromagnetic resonance region. We show that at small values of system
parameters, namely, damping, spin-orbit interaction, and Josephson to magnetic
energy ratio, the mag... | 2210.00366v1 |
2023-12-16 | Spin-torque nano-oscillator based on two in-plane magnetized synthetic ferrimagnets | We report the dynamic characterization of the spin-torque-driven in-plane
precession modes of a spin-torque nano-oscillator based on two different
synthetic ferrimagnets: a pinned one characterized by a strong RKKY interaction
which is exchange coupled to an antiferromagnetic layer; and a second one,
non-pinned charact... | 2312.10451v2 |
2013-08-17 | Thickness and power dependence of the spin-pumping effect in Y3Fe5O12/Pt heterostructures measured by the inverse spin Hall effect | The dependence of the spin-pumping effect on the yttrium iron garnet
(Y3Fe5O12, YIG) thickness detected by the inverse spin Hall effect (ISHE) has
been investigated quantitatively. Due to the spin-pumping effect driven by the
magnetization precession in the ferrimagnetic insulator YIG film a
spin-polarized electron cur... | 1308.3787v1 |
2020-05-28 | Spintronics meets nonadiabatic molecular dynamics: Geometric spin torque and damping on noncollinear classical magnetism due to electronic open quantum system | We analyze a quantum-classical hybrid system of steadily precessing slow
classical localized magnetic moments, forming a head-to-head domain wall,
embedded into an open quantum system of fast nonequilibrium electrons. The
electrons reside within a metallic wire connected to macroscopic reservoirs.
The model captures th... | 2005.14153v2 |
2020-09-29 | Structural Phase Dependent Giant Interfacial Spin Transparency in W/CoFeB Thin Film Heterostructure | Pure spin current has transfigured the energy-efficient spintronic devices
and it has the salient characteristic of transport of the spin angular
momentum. Spin pumping is a potent method to generate pure spin current and for
its increased efficiency high effective spin-mixing conductance (Geff) and
interfacial spin tr... | 2009.14143v1 |
2023-12-31 | Molecular Hybridization Induced Antidamping and Sizable Enhanced Spin-to-Charge Conversion in Co20Fe60B20/$β$-W/C60 Heterostructures | Development of power efficient spintronics devices has been the compelling
need in the post-CMOS technology era. The effective tunability of
spin-orbit-coupling (SOC) in bulk and at the interfaces of hybrid materials
stacking is a prerequisite for scaling down the dimension and power consumption
of these devices. In th... | 2401.00486v1 |
2002-04-25 | Statics and Fast Dynamics of Nanomagnets with Vortex Structure | Within the framework of the Landau-Lifshitz-Gilbert equation, using permalloy
parameters, we study the statics and dynamics of flat circular magnetic
nano-structures with an in-plane magnetic vortex configuration, putting
particular emphasis on the (planar) vorticity of the magnetic state and on the
(perpendicular) pol... | 0204541v3 |
2007-03-15 | Functional Keldysh Theory of Spin Torques | We present a microscopic treatment of current-induced torques and thermal
fluctuations in itinerant ferromagnets based on a functional formulation of the
Keldysh formalism. We find that the nonequilibrium magnetization dynamics is
governed by a stochastic Landau-Lifschitz-Gilbert equation with spin transfer
torques. We... | 0703414v2 |
2010-10-04 | Thermal fluctuation field for current-induced domain wall motion | Current-induced domain wall motion in magnetic nanowires is affected by
thermal fluctuation. In order to account for this effect, the
Landau-Lifshitz-Gilbert equation includes a thermal fluctuation field and
literature often utilizes the fluctuation-dissipation theorem to characterize
statistical properties of the ther... | 1010.0478v2 |
2015-06-03 | Antidamping spin-orbit torque driven by spin-flip reflection mechanism on the surface of a topological insulator: A time-dependent nonequilibrium Green function approach | Motivated by recent experiments observing spin-orbit torque (SOT) acting on
the magnetization $\vec{m}$ of a ferromagnetic (F) overlayer on the surface of
a three-dimensional topological insulator (TI), we investigate the origin of
the SOT and the magnetization dynamics in such systems. We predict that lateral
F/TI bil... | 1506.01303v3 |
2015-07-11 | Realization of the thermal equilibrium in inhomogeneous magnetic systems by the Landau-Lifshitz-Gilbert equation with stochastic noise, and its dynamical aspects | It is crucially important to investigate effects of temperature on magnetic
properties such as critical phenomena, nucleation, pinning, domain wall motion,
coercivity, etc. The Landau-Lifshitz-Gilbert (LLG) equation has been applied
extensively to study dynamics of magnetic properties. Approaches of Langevin
noises hav... | 1507.03075v1 |
2017-01-12 | Dynamic coupling of ferromagnets via spin Hall magnetoresistance | The synchronized magnetization dynamics in ferromagnets on a nonmagnetic
heavy metal caused by the spin Hall effect is investigated theoretically. The
direct and inverse spin Hall effects near the ferromagnetic/nonmagnetic
interface generate longitudinal and transverse electric currents. The
phenomenon is known as the ... | 1701.03201v2 |
2018-10-16 | Superfluid spin transport in ferro- and antiferromagnets | This paper focuses on spin superfluid transport, observation of which was
recently reported in antiferromagnet Cr$_2$O$_3$ [Yuan et al., Sci. Adv. 4,
eaat1098 (2018)]. This paper analyzes the role of dissipation in transformation
of spin current injected with incoherent magnons to a superfluid spin current
near the int... | 1810.07020v4 |
2020-02-20 | Stoner-Wohlfarth switching of the condensate magnetization in a dipolar spinor gas and the metrology of excitation damping | We consider quasi-one-dimensional dipolar spinor Bose-Einstein condensates in
the homogeneous-local-spin-orientation approximation, that is with
unidirectional local magnetization. By analytically calculating the exact
effective dipole-dipole interaction, we derive a Landau-Lifshitz-Gilbert
equation for the dissipative... | 2002.08723v2 |
2022-06-20 | First-principles calculation of the parameters used by atomistic magnetic simulations | While the ground state of magnetic materials is in general well described on
the basis of spin density functional theory (SDFT), the theoretical description
of finite-temperature and non-equilibrium properties require an extension
beyond the standard SDFT. Time-dependent SDFT (TD-SDFT), which give for example
access to... | 2206.09969v1 |
2023-09-25 | Ultrafast Demagnetization through Femtosecond Generation of Non-thermal Magnons | Ultrafast laser excitation of ferromagnetic metals gives rise to correlated,
highly non-equilibrium dynamics of electrons, spins and lattice, which are,
however, poorly described by the widely-used three-temperature model (3TM).
Here, we develop a fully ab-initio parameterized out-of-equilibrium theory
based on a quant... | 2309.14167v3 |
2023-12-12 | Sliding Dynamics of Current-Driven Skyrmion Crystal and Helix in Chiral Magnets | The skyrmion crystal (SkX) and helix (HL) phases, present in typical chiral
magnets, can each be considered as forms of density waves but with distinct
topologies. The SkX exhibits gyrodynamics analogous to electrons under a
magnetic field, while the HL state resembles topological trivial spin density
waves. However, u... | 2312.07116v2 |
2023-08-14 | Temperature Evolution of Magnon Propagation Length in Tm$_3$Fe$_5$O$_{12}$ Thin Films: Roles of Magnetic Anisotropy and Gilbert Damping | The magnon propagation length ($\langle\xi\rangle$) of a ferro/ferrimagnet
(FM) is one of the key factors that controls the generation and propagation of
thermally-driven spin current in FM/heavy metal (HM) bilayer based
spincaloritronic devices. Theory predicts that for the FM layer,
$\langle\xi\rangle$ is inversely p... | 2308.07236v3 |
2014-01-08 | Dynamic exchange via spin currents in acoustic and optical modes of ferromagnetic resonance in spin-valve structures | Two ferromagnetic layers magnetically decoupled by a thick normal metal
spacer layer can be, nevertheless, dynamically coupled via spin currents
emitted by the spin-pump and absorbed through the spin-torque effects at the
neighboring interfaces. A decrease of damping in both layers due to a partial
compensation of the ... | 1401.1672v1 |
2020-08-29 | Exploring a quantum-information-relevant magnonic material: Ultralow damping at low temperature in the organic ferrimagnet V[TCNE]x | Quantum information science and engineering requires novel low-loss magnetic
materials for magnon-based quantum-coherent operations. The search for low-loss
magnetic materials, traditionally driven by applications in microwave
electronics near room-temperature, has gained additional constraints from the
need to operate... | 2008.13061v3 |
2003-04-18 | Elementary Excitations of Ferromagnetic Metal Nanoparticles | We present a theory of the elementary spin excitations in transition metal
ferromagnet nanoparticles which achieves a unified and consistent quantum
description of both collective and quasiparticle physics. The theory starts by
recognizing the essential role played by spin-orbit interactions in determining
the energies... | 0304427v1 |
2014-08-02 | Tunnel magnetoresistance and spin-transfer-torque switching in polycrystalline Co2FeAl full-Heusler alloy magnetic tunnel junctions on Si/SiO2 amorphous substrates | We studied polycrystalline B2-type Co2FeAl (CFA) full-Heusler alloy based
magnetic tunnel junctions (MTJs) fabricated on a Si/SiO2 amorphous substrate.
Polycrystalline CFA films with a (001) orientation, a high B2 ordering, and a
flat surface were achieved using a MgO buffer layer. A tunnel magnetoresistance
(TMR) rati... | 1408.0341v1 |
2018-02-20 | Ultrafast magnetization dynamics in pure and doped Heusler and inverse Heusler alloys | By using a multiscale approach based on first-principles density functional
theory combined with atomistic spin dynamics, we investigate the electronic
structure and magnetization dynamics of an inverse Heusler and a Heusler
compound and their alloys, i. e. Mn$_{2-x}Z_x$CoAl and Mn$_{2-x}Z_x$VAl, where
$Z$ = Mo, W, Os ... | 1802.07195v1 |
2018-04-10 | GONG Catalog of Solar Filament Oscillations Near Solar Maximum | We have catalogued 196 filament oscillations from the GONG $H{\alpha}$
network data during several months near the maximum of solar cycle 24 (January
- June 2014). Selected examples from the catalog are described in detail, along
with our statistical analyses of all events. Oscillations were classified
according to the... | 1804.03743v1 |
2018-10-16 | Spin-wave-induced lateral temperature gradient in a YIG thin film/GGG system excited in an ESR cavity | Lateral thermal gradient of an yttrium iron garnet (YIG) film under the
microwave application in the cavity of the electron spin resonance system (ESR)
was measured at room temperature by fabricating a Cu/Sb thermocouple onto it.
To date, thermal transport in YIG films caused by the Damon-Eshbach mode (DEM)
- the unidi... | 1810.06875v1 |
2019-11-21 | Low damping and microstructural perfection of sub-40nm-thin yttrium iron garnet films grown by liquid phase epitaxy | The field of magnon spintronics is experiencing an increasing interest in the
development of solutions for spin-wave-based data transport and processing
technologies that are complementary or alternative to modern CMOS
architectures. Nanometer-thin yttrium iron garnet (YIG) films have been the
gold standard for insulat... | 1911.09400v1 |
2021-08-24 | Shape anisotropy effect on magnetization reversal induced by linear down chirp pulse | We investigate the influence of shape anisotropy on the magnetization
reversal of a single-domain magnetic nanoparticle driven by a circularly
polarized linear down-chirp microwave field pulse (DCMP). Based on the
Landau-Lifshitz-Gilbert equation, numerical results show that the three
controlling parameters of DCMP, na... | 2108.10965v2 |
2021-11-23 | Resonant dynamics of skyrmion lattices in thin film multilayers: Localised modes and spin wave emission | The spectral signatures of magnetic skyrmions under microwave field
excitation are of fundamental interest and can be an asset for high frequency
applications. These topological solitons can be tailored in multilayered thin
films, but the experimental observation of their spin wave dynamics remains
elusive, in particul... | 2111.11797v2 |
2022-05-20 | Effects of Crystalline Disorder on Interfacial and Magnetic Properties of Sputtered Topological Insulator/Ferromagnet Heterostructures | Thin films of Topological insulators (TIs) coupled with ferromagnets (FMs)
are excellent candidates for energy-efficient spintronics devices. Here, the
effect of crystalline structural disorder of TI on interfacial and magnetic
properties of sputter-deposited TI/FM, Bi2Te3/Ni80Fe20, heterostructures is
reported. Ni and... | 2205.09913v1 |
2022-12-24 | Anatomy of ultrafast quantitative magneto-acoustics in freestanding nickel thin films | We revisit the quantitative analysis of the ultrafast magneto-acoustic
experiment in a freestanding nickel thin film by Kim and Bigot [1] by applying
our recently proposed approach of magnetic and acoustic eigenmodes
decomposition by Vernik et al. [2]. We show that the application of our
modeling to the analysis of tim... | 2212.12673v1 |
2023-05-16 | Non-Hermitian Casimir Effect of Magnons | There has been a growing interest in non-Hermitian quantum mechanics. The key
concepts of quantum mechanics are quantum fluctuations. Quantum fluctuations of
quantum fields confined in a finite-size system induce the zero-point energy
shift. This quantum phenomenon, the Casimir effect, is one of the most striking
pheno... | 2305.09231v1 |
2002-09-07 | Neural network analysis of the magnetization reversal in magnetic dot arrays | We simulated the remagnetization dynamics of the ultra-dense and ultra-thin
magnetic dot array system with dipole-dipole and exchange coupling
interactions. Within the proposed 2D XY superlattice model, the square dots are
modeled by the spatially modulated exchange-couplings. The dipole-dipole
interactions were approx... | 0209186v1 |
2005-04-06 | Macrospin Models of Spin Transfer Dynamics | The current-induced magnetization dynamics of a spin valve are studied using
a macrospin (single domain) approximation and numerical solutions of a
generalized Landau-Lifshitz-Gilbert equation. For the purpose of quantitative
comparison with experiment [Kiselev {\it et al.} Nature {\bf 425}, 380 (2003)],
we calculate t... | 0504142v1 |
2006-02-01 | Mapping Monte Carlo to Langevin dynamics: A Fokker-Planck approach | We propose a general method of using the Fokker-Planck equation (FPE) to link
the Monte-Carlo (MC) and the Langevin micromagnetic schemes. We derive the
drift and disusion FPE terms corresponding to the MC method and show that it is
analytically equivalent to the stochastic Landau-Lifshitz-Gilbert (LLG)
equation of Lan... | 0602011v2 |
2006-04-21 | Dynamic approach for micromagnetics close to the Curie temperature | In conventional micromagnetism magnetic domain configurations are calculated
based on a continuum theory for the magnetization which is assumed to be of
constant length in time and space. Dynamics is usually described with the
Landau-Lifshitz-Gilbert (LLG) equation the stochastic variant of which includes
finite temper... | 0604508v1 |
2007-02-20 | Spin dynamics in a superconductor / ferromagnet proximity system | The ferromagnetic resonance of thin sputtered Ni80Fe20 films grown on Nb is
measured. By varying the temperature and thickness of the Nb the role of the
superconductivity on the whole ferromagnetic layer in these heterostructures is
explored. The change in the spin transport properties below the superconducting
transit... | 0702461v1 |
2007-02-21 | Domain wall mobility, stability and Walker breakdown in magnetic nanowires | We present an analytical calculation of the velocity of a single 180 degree
domain wall in a magnetic structure with reduced thickness and/or lateral
dimension under the combined action of an external applied magnetic field and
an electrical current. As for the case of field-induced domain wall propagation
in thick fil... | 0702492v1 |
2001-01-09 | Hysteresis in layered spring magnets | This article addresses a problem of micromagnetics: the reversal of magnetic
moments in layered spring magnets. A one-dimensional model is used of a film
consisting of several atomic layers of a soft material on top of several atomic
layers of a hard material. Each atomic layer is taken to be uniformly
magnetized, and ... | 0101077v1 |
2005-01-01 | Equatorial and related non-equilibrium states in magnetization dynamics of ferromagnets: Generalization of Suhl's spin-wave instabilities | We investigate the nonlinear dynamics underlying the evolution of a 2-D
nanoscale ferromagnetic film with uniaxial anisotropy in the presence of
perpendicular pumping. Considering the associated Landau-Lifshitz spin
evolution equation with Gilbert damping together with Maxwell equation for the
demagnetization field, we... | 0501002v2 |
2002-12-30 | Stochastic resonance in periodic potentials: realization in a dissipative optical lattice | We have observed the phenomenon of stochastic resonance on the Brillouin
propagation modes of a dissipative optical lattice. Such a mode has been
excited by applying a moving potential modulation with phase velocity equal to
the velocity of the mode. Its amplitude has been characterized by the
center-of-mass (CM) veloc... | 0212156v1 |
2007-05-03 | Planar spin-transfer device with a dynamic polarizer | In planar nano-magnetic devices magnetization direction is kept close to a
given plane by the large easy-plane magnetic anisotropy, for example by the
shape anisotropy in a thin film. In this case magnetization shows effectively
in-plane dynamics with only one angle required for its description. Moreover,
the motion ca... | 0705.0406v1 |
2007-05-03 | Effective attraction induced by repulsive interaction in a spin-transfer system | In magnetic systems with dominating easy-plane anisotropy the magnetization
can be described by an effective one dimensional equation for the in-plane
angle. Re-deriving this equation in the presence of spin-transfer torques, we
obtain a description that allows for a more intuitive understanding of
spintronic devices' ... | 0705.0508v1 |
2007-06-21 | Spin pumping by a field-driven domain wall | We calculate the charge current in a metallic ferromagnet to first order in
the time derivative of the magnetization direction. Irrespective of the
microscopic details, the result can be expressed in terms of the conductivities
of the majority and minority electrons and the non-adiabatic spin transfer
torque parameter ... | 0706.3160v3 |
2007-09-18 | Theory of current-driven magnetization dynamics in inhomogeneous ferromagnets | We give a brief account of recent developments in the theoretical
understanding of the interaction between electric currents and inhomogeneous
ferromagnetic order parameters. We start by discussing the physical origin of
the spin torques responsible for this interaction and construct a
phenomenological description. We ... | 0709.2937v2 |
2008-02-12 | Temperature dependent magnetization dynamics of magnetic nanoparticles | Recent experimental and theoretical studies show that the switching behavior
of magnetic nanoparticles can be well controlled by external time-dependent
magnetic fields. In this work, we inspect theoretically the influence of the
temperature and the magnetic anisotropy on the spin-dynamics and the switching
properties ... | 0802.1740v1 |
2008-05-21 | Non-equilibrium thermodynamic study of magnetization dynamics in the presence of spin-transfer torque | The dynamics of magnetization in the presence of spin-transfer torque was
studied. We derived the equation for the motion of magnetization in the
presence of a spin current by using the local equilibrium assumption in
non-equilibrium thermodynamics. We show that, in the resultant equation, the
ratio of the Gilbert damp... | 0805.3306v1 |
2008-06-28 | Theory of spin magnetohydrodynamics | We develop a phenomenological hydrodynamic theory of coherent magnetic
precession coupled to electric currents. Exchange interaction between electron
spin and collective magnetic texture produces two reciprocal effects:
spin-transfer torque on the magnetic order parameter and the Berry-phase gauge
field experienced by ... | 0806.4656v2 |
2008-09-25 | The theory of magnetic field induced domain-wall propagation in magnetic nanowires | A global picture of magnetic domain wall (DW) propagation in a nanowire
driven by a magnetic field is obtained: A static DW cannot exist in a
homogeneous magnetic nanowire when an external magnetic field is applied. Thus,
a DW must vary with time under a static magnetic field. A moving DW must
dissipate energy due to t... | 0809.4311v1 |
2008-10-08 | Transverse spin diffusion in ferromagnets | We discuss the dissipative diffusion-type term of the form
$\mathbf{m}\times\nabla^2\partial_t\mathbf{m}$ in the phenomenological
Landau-Lifshitz equation of ferromagnetic precession, which describes enhanced
Gilbert damping of finite-momentum spin waves. This term arises physically from
itinerant-electron spin flows t... | 0810.1340v2 |
2008-10-16 | Interaction of reed and acoustic resonator in clarinetlike systems | Sound emergence in clarinetlike instruments is investigated in terms of
instability of the static regime. Various models of reed-bore coupling are
considered, from the pioneering work of Wilson and Beavers ["Operating modes of
the clarinet", J. Acoust. Soc. Am. 56, 653--658 (1974)] to more recent modeling
including vis... | 0810.2870v1 |
2008-11-13 | Intrinsic Coupling between Current and Domain Wall Motion in (Ga,Mn)As | We consider current-induced domain wall motion and, the reciprocal process,
moving domain wall-induced current. The associated Onsager coefficients are
expressed in terms of scattering matrices. Uncommonly, in (Ga,Mn)As, the
effective Gilbert damping coefficient $\alpha_w$ and the effective out-of-plane
spin transfer t... | 0811.2235v2 |
2008-11-21 | Spin Transfer Torque as a Non-Conservative Pseudo-Field | In this paper we show that the spin transfer torque can be described by a
pseudo magnetic field, proportional to the magnetic moment of the itinerant
electrons that enters the Landau-Lifshitz-Gilbert equation in the same way as
other external or internal magnetic fields. However, unlike an ordinary
magnetic field, whic... | 0811.3472v1 |
2008-12-13 | Non-Adiabatic Spin Transfer Torque in Real Materials | The motion of simple domain walls and of more complex magnetic textures in
the presence of a transport current is described by the
Landau-Lifshitz-Slonczewski (LLS) equations. Predictions of the LLS equations
depend sensitively on the ratio between the dimensionless material parameter
$\beta$ which characterizes non-ad... | 0812.2570v1 |
2009-05-01 | Spin excitations in a monolayer scanned by a magnetic tip | Energy dissipation via spin excitations is investigated for a hard
ferromagnetic tip scanning a soft magnetic monolayer. We use the classical
Heisenberg model with Landau-Lifshitz-Gilbert (LLG)-dynamics including a
stochastic field representing finite temperatures. The friction force depends
linearly on the velocity (p... | 0905.0112v2 |
2009-05-29 | Ferromagnetic resonance linewidth in ultrathin films with perpendicular magnetic anisotropy | Transition metal ferromagnetic films with perpendicular magnetic anisotropy
(PMA) have ferromagnetic resonance (FMR) linewidths that are one order of
magnitude larger than soft magnetic materials, such as pure iron (Fe) and
permalloy (NiFe) thin films. A broadband FMR setup has been used to investigate
the origin of th... | 0905.4779v2 |
2009-10-01 | Spin motive forces and current fluctuations due to Brownian motion of domain walls | We compute the power spectrum of the noise in the current due to spin motive
forces by a fluctuating domain wall. We find that the power spectrum of the
noise in the current is colored, and depends on the Gilbert damping, the spin
transfer torque parameter $\beta$, and the domain-wall pinning potential and
magnetic ani... | 0910.0163v1 |
2009-10-08 | Fast domain wall propagation under an optimal field pulse in magnetic nanowires | We investigate field-driven domain wall (DW) propagation in magnetic
nanowires in the framework of the Landau-Lifshitz-Gilbert equation. We propose
a new strategy to speed up the DW motion in a uniaxial magnetic nanowire by
using an optimal space-dependent field pulse synchronized with the DW
propagation. Depending on ... | 0910.1477v2 |
2009-11-24 | Origin of adiabatic and non-adiabatic spin transfer torques in current-driven magnetic domain wall motion | A consistent theory to describe the correlated dynamics of quantum mechanical
itinerant spins and semiclassical local magnetization is given. We consider the
itinerant spins as quantum mechanical operators, whereas local moments are
considered within classical Lagrangian formalism. By appropriately treating
fluctuation... | 0911.4628v1 |
2010-01-26 | Strategies and tolerances of spin transfer torque switching | Schemes of switching nanomagnetic memories via the effect of spin torque with
various polarizations of injected electrons are studied. Simulations based on
macrospin and micromagnetic theories are performed and compared. We demonstrate
that switching with perpendicularly polarized current by short pulses and free
prece... | 1001.4578v1 |
2010-03-31 | Magnonic Crystal with Two-Dimensional Periodicity as a Waveguide for Spin Waves | We describe a simple method of including dissipation in the spin wave band
structure of a periodic ferromagnetic composite, by solving the Landau-Lifshitz
equation for the magnetization with the Gilbert damping term. We use this
approach to calculate the band structure of square and triangular arrays of Ni
nanocylinder... | 1003.6092v1 |
2010-07-20 | Precessing vortices and antivortices in ferromagnetic elements | A micromagnetic numerical study of the precessional motion of the vortex and
antivortex states in soft ferromagnetic circular nanodots is presented using
Landau-Lifshitz-Gilbert dynamics. For sufficiently small dot thickness and
diameter, the vortex state is metastable and spirals toward the center of the
dot when its ... | 1007.3508v1 |
2010-08-03 | Determination of the spin-flip time in ferromagnetic SrRuO3 from time-resolved Kerr measurements | We report time-resolved Kerr effect measurements of magnetization dynamics in
ferromagnetic SrRuO3. We observe that the demagnetization time slows
substantially at temperatures within 15K of the Curie temperature, which is ~
150K. We analyze the data with a phenomenological model that relates the
demagnetization time t... | 1008.0674v1 |
2010-10-07 | Power optimization for domain wall motion in ferromagnetic nanowires | The current mediated domain-wall dynamics in a thin ferromagnetic wire is
investigated. We derive the effective equations of motion of the domain wall.
They are used to study the possibility to optimize the power supplied by
electric current for the motion of domain walls in a nanowire. We show that a
certain resonant ... | 1010.1537v1 |
2011-03-30 | Spin motive forces due to magnetic vortices and domain walls | We study spin motive forces, i.e, spin-dependent forces, and voltages induced
by time-dependent magnetization textures, for moving magnetic vortices and
domain walls. First, we consider the voltage generated by a one-dimensional
field-driven domain wall. Next, we perform detailed calculations on
field-driven vortex dom... | 1103.5858v3 |
2011-07-04 | Influence of randomness and retardation on the FMR-linewidth | The theory predicts that the spin-wave lifetime $\tau_L$ and the linewidth of
ferromagnetic resonance $\Delta B$ can be governed by random fields and spatial
memory. To that aim the effective field around which the magnetic moments
perform a precession is superimposed by a stochastic time dependent magnetic
field with ... | 1107.0638v1 |
2011-11-18 | Charge and Spin Transport in Magnetic Tunnel Junctions: Microscopic Theory | We study the charge and spin currents passing through a magnetic tunnel
junction (MTJ) on the basis of a tight-binding model. The currents are
evaluated perturbatively with respect to the tunnel Hamiltonian. The charge
current has the form $A[\bm M_1(t)\times\dot{\bm M}_1(t)]\cdot\bm M_2+B\dot{\bm
M}_1(t)\cdot\bm M_2$,... | 1111.4295v2 |
2012-01-17 | Magnetic vortex echoes: application to the study of arrays of magnetic nanostructures | We propose the use of the gyrotropic motion of vortex cores in nanomagnets to
produce a magnetic echo, analogous to the spin echo in NMR. This echo occurs
when an array of nanomagnets, e.g., nanodisks, is magnetized with an in-plane
(xy) field, and after a time \tau a field pulse inverts the core magnetization;
the ech... | 1201.3553v1 |
2012-02-15 | Current-induced motion of a transverse magnetic domain wall in the presence of spin Hall effect | We theoretically study the current-induced dynamics of a transverse magnetic
domain wall in bi-layer nanowires consisting of a ferromagnet on top of a
nonmagnet having strong spin-orbit coupling. Domain wall dynamics is
characterized by two threshold current densities, $J_{th}^{WB}$ and
$J_{th}^{REV}$, where $J_{th}^{W... | 1202.3450v1 |
2012-04-23 | Rotating skyrmion lattices by spin torques and field or temperature gradients | Chiral magnets like MnSi form lattices of skyrmions, i.e. magnetic whirls,
which react sensitively to small electric currents j above a critical current
density jc. The interplay of these currents with tiny gradients of either the
magnetic field or the temperature can induce a rotation of the magnetic pattern
for j>jc.... | 1204.5051v1 |
2012-07-09 | Thermal vortex dynamics in thin circular ferromagnetic nanodisks | The dynamics of gyrotropic vortex motion in a thin circular nanodisk of soft
ferromagnetic material is considered. The demagnetization field is calculated
using two-dimensional Green's functions for the thin film problem and fast
Fourier transforms. At zero temperature, the dynamics of the
Landau-Lifshitz-Gilbert equat... | 1207.2192v2 |
2013-02-19 | Chirality Sensitive Domain Wall Motion in Spin-Orbit Coupled Ferromagnets | Using the Lagrangian formalism, we solve analytically the equations of motion
for current-induced domain-wall dynamics in a ferromagnet with Rashba
spin-orbit coupling. An exact solution for the domain wall velocity is
provided, including the effect of non-equilibrium conduction electron
spin-density, Gilbert damping, ... | 1302.4744v1 |
2013-12-17 | Control of the in-plane anisotropy in off-stoichiometric NiMnSb | NiMnSb is a ferromagnetic half-metal which, because of its rich anisotropy
and very low Gilbert damping, is a promising candidate for applications in
information technologies. We have investigated the in-plane anisotropy
properties of thin, MBE-grown NiMnSb films as a function of their Mn
concentration. Using ferromagn... | 1312.4781v2 |
2014-05-09 | Current-induced magnetization dynamics in two magnetic insulators separated by a normal metal | We study the dynamics of spin valves consisting of two layers of magnetic
insulators separated by a normal metal in the macrospin model. A current
through the spacer generates a spin Hall current that can actuate the
magnetization via the spin-transfer torque. We derive expressions for the
effective Gilbert damping and... | 1405.2267v1 |
2014-05-25 | Spin Hall phenomenology of magnetic dynamics | We study the role of spin-orbit interactions in the coupled magnetoelectric
dynamics of a ferromagnetic film coated with an electrical conductor. While the
main thrust of this work is phenomenological, several popular simple models are
considered microscopically in some detail, including Rashba and Dirac
two-dimensiona... | 1405.6354v2 |
2014-08-21 | Brownian motion of massive skyrmions forced by spin polarized currents | We report on the thermal effects on the motion of current-driven massive
magnetic skyrmions. The reduced equation for the motion of skyrmion has the
form of a stochastic generalized Thiele's equation. We propose an ansatz for
the magnetization texture of a non-rigid single skyrmion that depends linearly
with the veloci... | 1408.4861v2 |
2014-11-11 | Capturing of a Magnetic Skyrmion with a Hole | Magnetic whirls in chiral magnets, so-called skyrmions, can be manipulated by
ultrasmall current densities. Here we study both analytically and numerically
the interactions of a single skyrmion in two dimensions with a small hole in
the magnetic layer. Results from micromagnetic simulations are in good
agreement with e... | 1411.2857v1 |
2014-12-01 | Dissipation due to pure spin-current generated by spin pumping | Based on spin-dependent transport theory and thermodynamics, we develop a
generalized theory of the Joule heating in the presence of a spin current.
Along with the conventional Joule heating consisting of an electric current and
electrochemical potential, it is found that the spin current and spin
accumulation give an ... | 1412.0688v1 |
2015-01-30 | Head-to-Head Domain Wall Structures in Wide Permalloy Strips | We analyze the equilibrium micromagnetic domain wall structures encountered
in Permalloy strips of a wide range of thicknesses and widths, with strip
widths up to several micrometers. By performing an extensive set of
micromagnetic simulations, we show that the equilibrium phase diagram of the
domain wall structures ex... | 1501.07731v1 |
2015-02-19 | Characterization of spin relaxation anisotropy in Co using spin pumping | Ferromagnets are believed to exhibit strongly anisotropic spin relaxation,
with relaxation lengths for spin longitudinal to magnetization significantly
longer than those for spin transverse to magnetization. Here we characterize
the anisotropy of spin relaxation in Co using the spin pumping contribution to
Gilbert damp... | 1502.05687v3 |
2015-03-26 | Thermophoresis of an Antiferromagnetic Soliton | We study dynamics of an antiferromagnetic soliton under a temperature
gradient. To this end, we start by phenomenologically constructing the
stochastic Landau-Lifshitz-Gilbert equation for an antiferromagnet with the aid
of the fluctuation-dissipation theorem. We then derive the Langevin equation
for the soliton's cent... | 1503.07854v2 |
2015-04-01 | Multiscale modeling of ultrafast element-specific magnetization dynamics of ferromagnetic alloys | A hierarchical multiscale approach to model the magnetization dynamics of
ferromagnetic ran- dom alloys is presented. First-principles calculations of
the Heisenberg exchange integrals are linked to atomistic spin models based
upon the stochastic Landau-Lifshitz-Gilbert (LLG) equation to calculate
temperature-dependent... | 1504.00199v1 |
2015-05-04 | High-topological-number magnetic skyrmions and topologically protected dissipative structure | The magnetic skyrmion with the topological number of unity ($Q=1$) is a
well-known nanometric swirling spin structure in the nonlinear $\sigma$ model
with the Dzyaloshinskii-Moriya interaction. Here, we show that magnetic
skyrmion with the topological number of two ($Q=2$) can be created and
stabilized by applying vert... | 1505.00522v2 |
2015-08-06 | Large spin-wave bullet in a ferrimagnetic insulator driven by spin Hall effect | Due to its transverse nature, spin Hall effects (SHE) provide the possibility
to excite and detect spin currents and magnetization dynamics even in magnetic
insulators. Magnetic insulators are outstanding materials for the investigation
of nonlinear phenomena and for novel low power spintronics applications because
of ... | 1508.01427v1 |
2015-12-02 | Bose-Einstein Condensation of Magnons Pumped by the Bulk Spin Seebeck Effect | We propose inducing Bose-Einstein condensation of magnons in a magnetic
insulator by a heat flow oriented toward its boundary. At a critical heat flux,
the oversaturated thermal gas of magnons accumulated at the boundary
precipitates the condensate, which then grows gradually as the thermal bias is
dialed up further. T... | 1512.00557v1 |
2016-01-10 | Interfacial Dzyaloshinskii-Moriya interaction, surface anisotropy energy,and spin pumping at spin orbit coupled Ir/Co interface | The interfacial Dzyaloshinskii-Moriya interaction (iDMI), surface anisotropy
energy, and spin pumping at the Ir/Co interface are experimentally investigated
by performing Brillouin light scattering. Contrary to previous reports, we
suggest that the sign of the iDMI at the Ir/Co interface is the same as in the
case of t... | 1601.02210v3 |
2016-02-23 | Relaxation of a classical spin coupled to a strongly correlated electron system | A classical spin which is antiferromagnetically coupled to a system of
strongly correlated conduction electrons is shown to exhibit unconventional
real-time dynamics which cannot be described by Gilbert damping. Depending on
the strength of the local Coulomb interaction, the two main electronic
dissipation channels, tr... | 1602.07317v2 |
2016-04-24 | Coupled Spin-Light dynamics in Cavity Optomagnonics | Experiments during the past two years have shown strong resonant
photon-magnon coupling in microwave cavities, while coupling in the optical
regime was demonstrated very recently for the first time. Unlike with
microwaves, the coupling in optical cavities is parametric, akin to
optomechanical systems. This line of rese... | 1604.07053v3 |
2016-05-12 | Classical limit of Rabi nutations in spins of ferromagnets | Rabi oscillations describe the interaction of a two-level system with a
rotating electromagnetic field. As such, they serve as the principle method for
manipulating quantum bits. By using a combination of femtosecond laser pulses
and microwave excitations, we have observed the classical form of Rabi
nutations in a ferr... | 1605.03996v1 |
2016-05-21 | Landau-Lifshitz theory of the magnon-drag thermopower | Metallic ferromagnets subjected to a temperature gradient exhibit a magnonic
drag of the electric current. We address this problem by solving a stochastic
Landau-Lifshitz equation to calculate the magnon-drag thermopower. The
long-wavelength magnetic dynamics result in two contributions to the
electromotive force actin... | 1605.06578v1 |
2016-06-07 | The temperature dependence of FeRh's transport properties | The finite-temperature transport properties of FeRh compounds are
investigated by first-principles Density Functional Theory-based calculations.
The focus is on the behavior of the longitudinal resistivity with rising
temperature, which exhibits an abrupt decrease at the metamagnetic transition
point, $T = T_m$ between... | 1606.02072v1 |
2016-09-05 | Coarsening dynamics of topological defects in thin Permalloy films | We study the dynamics of topological defects in the magnetic texture of
rectangular Permalloy thin film elements during relaxation from random
magnetization initial states. Our full micromagnetic simulations reveal complex
defect dynamics during relaxation towards the stable Landau closure domain
pattern, manifested as... | 1609.01094v1 |
2016-09-27 | Anomalous Feedback and Negative Domain Wall Resistance | Magnetic induction can be regarded as a negative feedback effect, where the
motive-force opposes the change of magnetic flux that generates the
motive-force. In artificial electromagnetics emerging from spintronics,
however, this is not necessarily the case. By studying the current-induced
domain wall dynamics in a cyl... | 1609.08250v1 |
2016-10-04 | Magnetomechanical coupling and ferromagnetic resonance in magnetic nanoparticles | We address the theory of the coupled lattice and magnetization dynamics of
freely suspended single-domain nanoparticles. Magnetic anisotropy generates
low-frequency satellite peaks in the microwave absorption spectrum and a
blueshift of the ferromagnetic resonance (FMR) frequency. The low-frequency
resonances are very ... | 1610.01072v2 |
2016-10-05 | Finite-dimensional colored fluctuation-dissipation theorem for spin systems | When nano-magnets are coupled to random external sources, their magnetization
becomes a random variable, whose properties are defined by an induced
probability density, that can be reconstructed from its moments, using the
Langevin equation, for mapping the noise to the dynamical degrees of freedom.
When the spin dynam... | 1610.01622v1 |
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