Exact Solution of an Ising Model with Three-Spin Interactions on a Triangular Lattice

Abstract

The Ising model on a triangular lattice with three-spin interactions is solved exactly. The solution, which is obtained by solving an equivalent coloring problem using the Bethe Ansatz method, is given in terms of a simple algebraic relation. The specific heat is found to diverge with indices $\ensuremath{\alpha}={\ensuremath{\alpha}}^{\ensuremath{'}}=\frac{2}{3}$.