High-temperature series analysis of an O(2)-symmetric spin model with discretely valued interaction on 2D lattices

Abstract

An analysis is given of high-temperature series expansions for the susceptibility of an O(2)-symmetric spin model with discretely valued spin-spin interaction on triangular and square lattices. This analysis does not yield strong evidence for a phase transition in either case, although it is weakly consistent with this possibility. The authors also comment on the high-temperature series for the free energy and specific heat.