Simulation of a multicritical fcc Ising antiferromagnet

Inspired by the work by Kaemmerer, Duenweg, Binder, and d'Onorio de Meo we investigated the spin-1/2 Ising antiferromagnet on a fcc lattice in a homogeneous external magnetic field H with uniform nearest-neighbor interaction J by Monte Carlo simulations. In order to answer the open question whether this system exhibits a triple point or a multicritical point for positive H, we mainly studied lattices with 4 - 323 and 4 - 723 spins. We found a multicritical point at (Hc, κBTc) = (3.49 ± 0.02, 1.02 ± 0.01)J in the thermodynamic limit