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.

7 pages (latex), 1 figure (ps file included), Landau LITP/3--CP--93, PAR--LPTHE 93--34 (format of the file for the figure has been changed)