Publication: Stochastic vortex dynamics in two-dimensional easy-plane ferromagnets: Multiplicative versus additive noise
Loading...
Identifiers
ISSN: 1098-0121 (print version)
ISSN: 1550-235X (online version)
Publication date
1999-05-01
Defense date
Advisors
Tutors
Journal Title
Journal ISSN
Volume Title
Publisher
American Physical Society
Abstract
We study how thermal fluctuations affect the dynamics of vortices in the two-dimensional classical, ferromagnetic,
anisotropic Heisenberg model depending on their additive or multiplicative character. Using a
collective coordinate theory, we analytically show that multiplicative noise, arising from fluctuations in the
local-field term of the Landau-Lifshitz equations, and Langevin-like additive noise both have the same effect
on vortex dynamics ~within a very plausible assumption consistent with the collective coordinate approach!.
This is a nontrivial result, as multiplicative and additive noises usually modify the dynamics quite differently.
We also carry out numerical simulations of both versions of the model finding that they indeed give rise to very
similar vortex dynamics.
Description
Keywords
Bibliographic citation
Physical Review B, vol. 59, n. 17, 1 may 1999. Pp. 11349-11357