Relaxation of the Spin Autocorrelation Function in the Ising Spin Glass

Relaxation phenomena are studied for the ±J Ising spin glass in two dimensions by Monte Carlo method. For each spin, a representative relaxation time of the spin is estimated from the equilibrium autocorrelation function of the spin. Clusters of slowly relaxing spins are found to exist below the critical temperature of the nonrandom Ising ferromagnet. It is also found that the distribution of the relaxation times of spins is consistent with the prediction of the theory which assumes independent motion of clusters. This distribution explains the nonexponential decay of the averaged spin autocorrelation function as in the case of the diluted Ising ferromagnets.