Numerically exact solvable random-bond Ising model

Abstract

Exact free energies are calculated numerically for aL×L-Ising lattice (LlE800) with constant nearest neighbour coupling between adjacent columns and random n.n. coupling between adjacent rows. For the latter a gaussian and a double-peaked delta-distribution are investigated. The result should be useful as a check of the controversially discussed replica trick [1]. In agreement with the numerical treatment a mean field approximation shows a transition to a spinglass phase.