NEW METHOD FOR DETERMINATION OF CRITICAL PARAMETERS

Our method uses topological properties of the large clusters in the single-cluster algorithm of Wolff for Monte Carlo simulations of spin systems. We have applied this method to the d = 3 Ising model with film geometry near the special transition. As a test for the method we determined the bulk critical temperature and the critical indices in fair agreement with the results obtained by other methods. The new results refer to the critical surface coupling J1c/J = 1.5004(20) and the surface exponents, where we found phi = 0.461(15) and beta1m = 0.237(5).