A Monte Carlo study of the first-order transition in a Heisenberg FCC antiferromagnet

A 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 one to overcome a slow relaxation of the magnetic order parameter and to fully equilibrate moderately sized clusters with up to N ≃ 7 × 103 spins. By collecting energy and order parameter histograms on clusters with up to N ≃ 2 × 104 sites, we accurately locate the first-order transition point at T c = 0.4459(1)J.