Critical Point Correlation Function for the 2D Random Coupling Ising Model

Abstract

High accuracy Monte Carlo simulation results for 1024*1024 Ising system with ferromagnetic impurity bonds are presented. Spin-spin correlation function at a critical point is found to be numerically very close to that of a pure system. This is not trivial since a critical temperature for the system with impurities is almost two times lower than pure Ising $T_c$. Small deviations from the pure behaviour contradict to some of the competing theories.