Dynamics of ferromagnetic nanomagnets with vortex or single-domain configuration

We study the dynamics of flat circular permalloy nanomagnets for (1) magnetic vortex and (2) single-domain configurations using micromagnetic simulation. Dynamical studies for isolated vortex structures show that both the vorticity and the polarity of the out-of-plane component can be switched fast (50-100 ps). Micromagnetic simulations of the switching process in thin cylindrical permalloy nanoparticles with an initial stable single-domain state show nearly homogeneous single-domain behaviour followed by excitation of spin waves. (C) 2003 Published by Elsevier B.V.