Relaxation of an isolated droplet in pure and random ising magnets: Monte Carlo simulation

Abstract

By Monte Carlo simulation the author investigated the relaxation of an isolated droplet in the two-dimensional pure Ising model below the ordering temperature T_c. For system sizes 180² and 240² the author observed a stretched exponential decay, namely C(t) approximately exp(-(t/ tau )^½ ), of the temporal spin autocorrelation function C(t) in the intermediate and long time regimes (of the order of 10⁴ Monte Carlo steps spin^-1). The author also computed the correlation function C(t) for the two-dimensional Ising model with quenched random site disorder out to 10⁵ Monte Carlo steps spin^-1 for system sizes up to 180². The relaxation is much slower in the latter model than in the pure Ising model.