Monte Carlo study of first-order transition in Heisenberg fcc antiferromagnet

TL;DR

This study uses advanced Monte Carlo simulations with parallel tempering to precisely identify the first-order phase transition temperature in a Heisenberg antiferromagnet on an fcc lattice, overcoming relaxation challenges.

Contribution

It introduces an extensive Monte Carlo approach with parallel tempering to accurately locate the first-order transition in a Heisenberg fcc antiferromagnet.

Findings

First-order transition at T_c=0.4459(1)J identified.

Parallel tempering effectively overcomes slow relaxation.

Large-scale simulations enable precise thermodynamic measurements.

Abstract

Nearest-neighbor Heisenberg antiferromagnet on a face-centered cubic lattice is studied by extensive Monte Carlo simulations in zero magnetic field. The parallel tempering algorithm is utilized, which allows to overcome a slow relaxation of the magnetic order parameter and fully equilibrate moderate size clusters with up to N ~ 7*10^3 spins. By collecting energy and order parameter histograms on clusters with up to N ~ 2*10^4 sites we accurately locate the first-order transition point at T_c=0.4459(1)J.