High temperature study of the Kosterlitz-Thouless phase transition in the XY model on the triangular lattice

TL;DR

This paper extends high temperature series expansions for the XY model on a triangular lattice, providing evidence supporting Kosterlitz-Thouless predictions and estimating critical parameters with improved accuracy.

Contribution

It introduces two additional terms in the high temperature series expansions and offers detailed analysis supporting the Kosterlitz-Thouless transition theory.

Findings

Series expansions extended to order beta^{14}

Supports Kosterlitz-Thouless critical singularity predictions

Provides accurate estimates of critical parameters

Abstract

High temperature series expansions of the spin-spin correlation function for the XY (or plane rotator) model on the triangular lattice are extended by two terms up to order beta^{14}. Tables of the expansion coefficients are reported for the correlation function spherical moments of order l=0 and 2. Our analysis of the series supports the Kosterlitz-Thouless predictions on the structure of the critical singularities and leads to fairly accurate estimates of the critical parameters.