Brownian motion

Physics

Ferromagnetism

Skyrmion

Motion (physics)

Equations of motion

Dynamics (music)

Coupling (piping)

Quasiparticle

Magnon

Acoustics

Metallurgy

Materials science

Heat equation

Condensed matter physics

Superconductivity

Quantum mechanics

Fokker–Planck equation

Differential equation

Classical mechanics

Dissipative system

Physical Review Letters

Magnetic textures are often treated as quasiparticles following Thiele's equation of motion. We demonstrate via spin model simulations of the current-driven and Brownian motion of ferromagnetic skyrmions that the existing theory based on Thiele's equation is insufficient to describe the dynamics of skyrmions at finite temperatures. We propose an extended equation of motion that goes beyond Thiele's equation by taking into account the coupling of the skyrmion to the magnonic heat bath leading to an additional dissipative term that is linear in temperature. Our results indicate that this so-far-neglected magnon-induced friction dominates for finite temperatures and Gilbert damping values typical for thin films and multilayers.Received 12 April 2021Revised 10 June 2021Accepted 21 June 2021DOI:https://doi.org/10.1103/PhysRevLett.127.047203© 2021 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBrownian motionSkyrmionsSpin currentSpin dynamicsSpin torquePhysical SystemsUltrathin filmsTechniquesLandau-Lifschitz-Gilbert equationCondensed Matter, Materials & Applied PhysicsStatistical Physics

Skyrmion Dynamics at Finite Temperatures: Beyond Thiele’s Equation