Double Potts Chain and Exact Results for Some Two-Dimensional Spin Models

摘要

An exact analytical solution for the q-state Potts model on a 2 * ∞ ladder with arbitrary two-, three-, and four-site interactions in a unit cell in presented is a closed form. This solution is used to show that the finitesize internal energy equation [6] yields an accurate value of the critical temperature for the triangular Potts lattice with three-site interactions in alternate triangular faces. It is argued that the above equation is exact at least for self-dual models on isotopic strips.