arXiv subjects
Publications and source records attributed to C Gerard.
The critical properties of the mixed ferro/antiferromagnetic q-state Potts model on the square lattice are investigated using the numerical transfer matrix technique. The transition temperature is found to be substantially lower than previously found for q=3. It is conjectured that there is no transition for q>3, in contradiction with previous results.
A numerical transfer matrix calculation is presented for two fully-frustrated three-state Potts models on the square lattice: the Potts piled-up-domino model and the Potts zig-zag model. The ground state entropies and phase diagrams are found. The Potts piled-up-domino model displays a finite-temperature transition when the frustration effects are maximal, and displays reentrant behaviour, in contrast to the Ising model equivalent. The ground-state entropy per spin is larger than in the Ising equivalent. The Potts zig-zag model displays the same qualitative behaviour as its Ising counterpart, and the ground-state entropy per spin is the same in the Potts and Ising cases.