Phase transition in the±JIsing-spin-glass model

Abstract

The two-dimensional $\pm J$ model (antiferromagnetic and ferromagnetic bonds at random) is studied by transfer-matrix and Monte Carlo calculations. Large clusters of spins pointing in one direction are found for $0.12<x\le 0.16$ ($x$ being the concentration of negative bonds). Evidence against a phase transition at finite temperature is found by investigating the correlation function ${〈S_0{S}_R〉}^2$..