STRETCHED AND NON-STRETCHED EXPONENTIAL RELAXATION IN ISING-FERROMAGNETS

The decay of the Hamming distance in Monte Carlo simulations of Ising models with model A dynamics is shown to be numerically efficient to i nvestigate the dynamics also below T-c. We observe a simple exponentia l decay in three and four dimensions below and above the Curie tempera ture. In two dimensions, a stretched exponential decay is observed onl y below T-c. The exponent in the latter is between the two predictions of Takano et al. and Huse and Fisher, but the dynamics of single drop lets is clearly found to disagree with Takano et al.