Noise-induced switching between vortex states with different polarization in classical two-dimensional easy-plane magnets
Condensed Matter
2009-10-31 v1
Abstract
In the 2-dimensional anisotropic Heisenberg model with XY-symmetry there are non-planar vortices which exhibit a localized structure of the z-components of the spins around the vortex center. We study how thermal noise induces a transition of this structure from one polarization to the opposite one. We describe the vortex core by a discrete Hamiltonian and consider a stationary solution of the Fokker-Planck equation. We find a bimodal distribution function and calculate the transition rate using Langer's instanton theory (1969). The result is compared with Langevin dynamics simulations for the full many-spin model.
Cite
@article{arxiv.cond-mat/9902144,
title = {Noise-induced switching between vortex states with different polarization in classical two-dimensional easy-plane magnets},
author = {Y. Gaididei and T. Kamppeter and F. G. Mertens and A. R. Bishop},
journal= {arXiv preprint arXiv:cond-mat/9902144},
year = {2009}
}
Comments
15 pages, 4 figures, Phys. Rev. B., in press