Rotationally symmetric ordered phase in the three-state antiferromagnetic Potts model

We investigate the three-state antiferromagnetic Potts model on a simple cubic lattice with a cluster flipping Monte Carlo simulation algorithm in the temperature region below the transition into disorder at ${\mathit{T}}_{\mathit{c}1}$. We find both the well-established broken-sublattice-symmetry (BSS) phase at low temperature and a rotationally symmetric phase at higher temperature, but below ${\mathit{T}}_{\mathit{c}1}$. The properties of the second phase and the transition temperature to the BSS phase are in disagreement with recent cluster-variation and Monte Carlo simulation results, but in agreement with simulations by Kolesik and Suzuki. © 1996 The American Physical Society.