Magnetization switching in nanowires: Monte Carlo study with fast Fourier transformation for dipolar fields

For the investigations of thermally activated magnetization reversal in sys tems of classical magnetic moments numerical methods are desirable. We pres ent numerical studies which base on time quantified Monte Carlo methods whe re the long-range dipole-dipole interaction is calculated with the aid of f ast Fourier transformation. As an example, we study models for ferromagneti c nanowires comparing our numerical results for the characteristic time of the reversal process also with numerical data from Langevin dynamics simula tions where the fast Fourier transformation method is well established. Dep ending on the system geometry different reversal mechanism occur like coher ent rotation, nucleation, and curling. (C) 2000 Elsevier Science B.V. All r ights reserved.