Partition function zeros of the antiferromagnetic Ising model on triangular lattice in the complex temperature plane for nonzero magnetic field

Abstract

The grand partition functions Z(T, B) of the Ising model on L x L triangular lattices with fully periodic boundary conditions, as a function of temperature T and magnetic field B, are evaluated exactly for L < 12 (using microcanonical transfer matrix) and approximately for L >= 12 (using Wang-Landau Monte Carlo algorithm). From Z(T, B), the distributions of the partition function zeros of the triangular-lattice Ising model in the complex temperature plane for real B 6 0 are obtained and discussed for the first time. The critical points a(N) (x) and the thermal scaling exponents y(t) (x) of the triangular-lattice Ising anti ferro magnet, for various values of x = e(-2 beta B), are estimated using the partition function zeros. (c) 2008 Elsevier B.V. All rights reserved.