Antiferromagnetic ordering in the three-state Potts model

摘要: The three-state Potts model on a triangular lattice with nearest neighbour interaction K is studied. Using simple position-space renormalisation group transformation it found that, in addition to the usual continuous transition ferromagnetic state which occurs for positive K, an antiferromagnetic negative K. introduces three-spin interaction. In space of these two interactions, lines and transitions meet at bicritical point. These results differ from those predicted by Landau theory.