Topological quantization of the flow of magnetic skyrmions driven by a ratchet-like potential under thermal fluctuations

Abstract

We consider a magnetic skyrmion adiabatically driven by a spin-polarized electrical current periodic in both space and time and asymmetric in space, and also subject to a random magnetic field representing the thermal fluctuations. We show that when the random magnetic field is low enough, while the time variation of the driving current is slow enough, the skyrmion flow is an integer multiply of the ratio between the space and time periods, the integer being a topological invariant called Chern number. This result is also demonstrated by numerically solving the stochastic Landau-Lifshitz-Gilbert (sLLG) and Langevin equations. Our work suggests a novel method of manipulating skyrmions with topological stability.

arXiv comment6 pages, 1 figure

References in corpus (13)

• Skyrmion Lattice in a Chiral Magnet
• Brownian motors: noisy transport far from equilibrium
• Spin Transfer Torques in MnSi at Ultra-low Current Densities
• Emergent electrodynamics of skyrmions in a chiral magnet
• Theory of current-driven motion of Skyrmions and spirals in helical magnets
• Thermally Driven Ratchet Motion of Skyrmion Microcrystal and Topological Magnon Hall Effect
• Dynamics of an Insulating Skyrmion under a Temperature Gradient
• Rotating skyrmion lattices by spin torques and field or temperature gradients
• AC current generation in chiral magnetic insulators and skyrmion motion induced by the spin Seebeck effect
• Magnus-Induced Ratchet Effects for Skyrmions Interacting with Asymmetric Substrates
• Brownian motion of massive skyrmions forced by spin polarized currents
• Thermally Assisted Current-Driven Skyrmion Motion
• Quantization and Corrections of Adiabatic Particle Transport in a Periodic Ratchet Potential

Cited by in corpus (1)

• Nonhermitian adiabatic perturbation theory of topological quantization of the average velocity of a magnetic skyrmion under thermal fluctuations