Anisotropic XY antiferromagnets in a field

TL;DR

This study uses Monte Carlo simulations to explore phase transitions in anisotropic XY antiferromagnets under a field, revealing different behaviors in two and three dimensions, including phase separation and bicritical points.

Contribution

It provides new insights into the phase diagrams of anisotropic XY antiferromagnets, highlighting the dimensional dependence of phase transitions and the nature of critical points.

Findings

In 2D, antiferromagnetic and spin-flop phases are separated by a narrow disordered phase.

In 3D, a first-order transition line and a bicritical point are identified.

Results align with and extend previous studies on similar systems.

Abstract

Classical anisotropic XY antiferromagnets in a field on square and simple cubic lattices are studied using mainly Monte Carlo simulations. While in two dimensions the ordered antiferromagnetic and spin--flop phases are observed to be separated by a narrow disordered phase, a line of direct transitions of first order between the two phases and a bicritical point are found in three dimensions. Results are compared to previous findings.