2019/01/31 by Le Zhao, Zidong Wang, Xichao Zhang +11 · 1 citation
Engineering · Mathematics · Physics and Astronomy · #Brownian motion #Characterization and Applications of Magnetic Nanoparticles #Combinatorics #Magnetic properties of thin films #Mathematics #Physics #Quantum mechanics #Skyrmion #Statistical physics #Theoretical and Computational Physics #Topology (electrical circuits) #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.125.027206
published as Physical Review Letters, 125, 027206 (2020)
openalex publication_date 2020/07/10 · arxiv created 2020/07/13 · arxiv updated 2020/11/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Noninteracting particles exhibiting Brownian motion have been observed in many occasions of sciences, such as molecules suspended in liquids, optically trapped microbeads, and spin textures in magnetic materials. In particular, a detailed examination of Brownian motion of spin textures is important for designing thermally stable spintronic devices, which motivates the present study. In this Letter, through using temporally and spatially resolved polar magneto-optic Kerr effect microscopy, we have experimentally observed the thermal fluctuation-induced random walk of a single isolated Néel-type magnetic skyrmion in an interfacially asymmetric Ta/CoFeB/TaOx multilayer. An intriguing topology-dependent Brownian gyromotion behavior of skyrmions has been identified. The onset of Brownian gyromotion of a single skyrmion induced by thermal effects, including a nonlinear temperature-dependent diffusion coefficient and topology-dependent gyromotion are further formulated based on the stochastic Thiele equation. The experimental and numerical demonstration of topology-dependent Brownian gyromotion of skyrmions can be useful for understanding the nonequilibrium magnetization dynamics and implementing spintronic devices.