Next: INTRODUCTION: VORTEX INSTABILITY
NORMAL MODES OF VORTICES IN EASY-PLANE FERROMAGNETS
G. M. Wysin
Department of Physics, Kansas State University,
Manhattan, KS 66506-2601
A. R. Völkel
University of Toronto, Toronto, Ontario, Canada, M5S 1A7
May 15, 1995
Abstract:
We investigate the linear spin wave spectrum of 2d easy-plane classical
Heisenberg ferromagnets in the presence of a vortex, using numerical
diagonalization on small systems. The spectra of normal modes for both
in-plane and out-of-plane vortices are determined, for square, triangular and
hexagonal lattices. Some of the modes show a strong localization of their
amplitudes near the center of the vortex. Moreover, we investigate a
particular mode that drives the crossover in the static vortex structure from
purely in-plane to a vortex with well-localized out-of-plane component as the
easy-plane character of the system is reduced below a certain threshold.
PACS numbers: 75.10.Hk, 75.30.Ds, 75.40.Gb, 75.40.Mg
Submitted to
Physical Review B
This preprint also available in RevTeX.
(A zipped file including postscript figures.)
Gary M Wysin
Mon Sep 11 12:02:10 CDT 1995