Correlation function behavior in the topological Kosterlitz–Thouless transition using the Replica-Exchange Wang–Landau technique

Abstract

In this paper, we use the Replica-Exchange Wang–Landau (REWL) technique to study the behavior of the two-point correlation function of the site diluted classical anisotropic Heisenberg (AH) model in two dimensions. The model has a topological Berezinskii–Kosterlitz–Thouless (BKT) transition for any dilution down to the percolation threshold, [Formula: see text]. Contrary to earlier results that predict the exponent of the correlation function, [Formula: see text], to decay linearly to zero as a function of temperature, we found that it decreases with temperature to a finite value [Formula: see text] at [Formula: see text] for any dilution [Formula: see text].