Field-induced Kosterlitz–Thouless transition in critical triangular-lattice antiferromagnets

Abstract

Abstract In this paper, we directly obtain from Monte Carlo simulations the critical magnetic field H = 0 . 29 ( 3 ) ${H=0.29(3)}$ of the field-induced Kosterlitz–Thouless transition in the critical triangular-lattice antiferromagnet. The Yang–Lee zero approach clearly shows the field-induced Kosterlitz–Thouless transition and the critical magnetic field agrees well with the results from other indirect methods. Also, the reduced zero-field susceptibility gives us the same conclusion. For the investigations, we used the exact and approximate ground densities of states as a function of magnetization by using both the exact enumeration method for small systems (up to 9×9 lattices) and the Wang–Landau Monte Carlo algorithm for large systems (up to 30×30 lattices).