Monte Carlo study on dynamical aspects of the 2D Gaussian Ising spin glass

Abstract

Dynamical aspects of the 2D Gaussian Ising spin glass are studied by a Monte Carlo simulation. The relaxation times tau i of individual spins in the system are determined by analysing their autocorrelation functions. The distribution of In tau i turns out to be broad, and rather homogeneous, and with the decreasing temperature its upper limit increases more rapidly than expected from the simple Arrhenius law. These tau i are shown to reproduce excellently most of the qualitative features of the total spin relaxation function and the complex AC susceptibility observed experimentally in various spin-glass systems. The authors argue then that the change of the tau i distribution by temperatures originates from the cooperative aspect of spin clusters, which themselves are by no means rigid even in the limited temperature range investigated.