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 × 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 ≠ 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 antiferromagnet, for various values of x = e − 2 β B , are estimated using the partition function zeros.