Effective temperature and Gilbert damping of a current-driven localized spin

Abstract

Starting from a model that consists of a semiclassical spin coupled to two leads we present a microscopic derivation of the Langevin equation for the direction of the spin. For slowly-changing direction it takes on the form of the stochastic Landau-Lifschitz-Gilbert equation. We give expressions for the Gilbert damping parameter and the strength of the fluctuations, including their bias-voltage dependence. At nonzero bias-voltage the fluctuations and damping are not related by the fluctuation-dissipation theorem. We find, however, that in the low-frequency limit it is possible to introduce a voltage-dependent effective temperature that characterizes the fluctuations in the direction of the spin, and its transport-steady-state probability distribution function.

8 pages, 2 figures. v2: published version

References in corpus (24)

• Real-space observation of current-driven domain wall motion in submicron magnetic wires
• Theory of Current-Driven Domain Wall Motion: A Poorman's Approach
• Thermally assisted magnetization reversal in the presence of a spin-transfer torque
• Switching a spin-valve back and forth by current-induced domain wall motion
• Current-Driven Magnetic Excitations in Permalloy-Based Multilayer Nanopillars
• Current-spin coupling for ferromagnetic domain walls in fine wires
• Nonequilibrium quantum criticality in open electronic systems
• Spin-torque switching: Fokker-Planck rate calculation
• Temperature dependence of spin-transfer-induced switching of nanomagnets
• Functional Keldysh Theory of Spin Torques
• Magnetization noise in magnetoelectronic nanostructures
• Stochastic Dynamics of a Trapped Bose-Einstein Condensate
• Current induced magnetization dynamics in current perpendicular to the plane spin valves
• On the perturbative expansion of the magnetization in the out-of-equilibrium Kondo model
• Spin and Spin-Wave Dynamics in Josephson Junctions
• Dynamics of magnetization coupled to a thermal bath of elastic modes
• Spin Dynamics in a Tunnel Junction between Ferromagnets
• Spin dynamics and violation of the fluctuation dissipation theorem in a non-equilibrium ohmic spin boson model
• Tunneling measurement of quantum spin oscillations
• Fluctuation-dissipation considerations and damping models for ferromagnetic materials
• Fluctuations of the Magnetization in Thin Films due to Conduction Electrons
• Effective temperature of a dissipative driven mesoscopic system
• Voltage dependence of Landau-Lifshitz-Gilbert damping of a spin in a current driven tunnel junction
• Comment on "Fluctuation-dissipation considerations and damping models for ferromagnetic thin-films"

Cited by in corpus (24)

• Spin-transfer torque on a single magnetic adatom
• Time-retarded damping and magnetic inertia in the Landau-Lifshitz-Gilbert equation self-consistently coupled to electronic time-dependent nonequilibrium Green functions
• Spin dynamics of current driven single magnetic adatoms and molecules
• Current-induced switching in transport through anisotropic magnetic molecules
• Spintronics meets nonadiabatic molecular dynamics: Geometric spin torque and damping on noncollinear classical magnetism due to electronic open quantum system
• Stochastic dynamics of magnetization in a ferromagnetic nanoparticle out of equilibrium
• Transient spin dynamics in a single-molecule magnet
• Magnetic dynamics with spin transfer torques near the Curie temperature
• Fluctuation Theorem for a Small Engine and Magnetization Switching by Spin Torque
• Driven quantum coarsening
• Gilbert damping in metallic ferromagnets from Schwinger-Keldysh field theory: Intrinsically nonlocal and nonuniform, and made anisotropic by spin-orbit coupling
• Annihilation of topological solitons in magnetism with spin wave burst finale: The role of nonequilibrium electrons causing nonlocal damping and spin pumping over ultrabroadband frequency range
• When can localized spins interacting with conduction electrons in ferro- or antiferromagnets be described classically via the Landau-Lifshitz equation: Transition from quantum many-body entangled to quantum-classical nonequilibrium states
• Quantum Brownian Motion of a Magnetic Skyrmion
• Quantum kinetic theory of spin-transfer torque and magnon-assisted transport in nanostructures
• Dynamical exchange and phase induced switching of a localized molecular spin
• Dynamics of spin relaxation in nonequilibrium magnetic nanojunctions
• Fluctuations of current-driven domain walls in the non-adiabatic regime
• Anisotropic skyrmion mass induced by surrounding conduction electrons: A Schwinger-Keldysh field theory approach
• Nonequilibrium dynamics in a spin valve with noncollinear magnetization
• Coarsening of Disordered Quantum Rotors under a Bias Voltage
• Microscopic theory of spin friction and dissipative spin dynamics
• Current driven defect unbinding transition in an XY ferromagnet
• Controllable and Non-Dissipative Inertial Dynamics of Skyrmion in a Bosonic Platform