Thermodynamic Properties of Antiferromagnetic Quantum XY-Model on the Triangular Lattice

抄録

Thermodynamic properties of antiferromagnetic quantum XY-model (s=1⁄2) on a triangular lattice are studied by the Decoupled Cell Monte Carlo Method (DCM). The decoupled cell (DC) used in this study consists of 7 spins. The size N of systems are 15*15, 30*30, 45*45, respectively. Detailed studies of spin pair correlation functions for both x- and z-components are performed at various temperatures. The results suggest that the existence of the shortrange three sublattice structure. The mean square magnetization of a sublattice for the x-component does not depend on N, whereas that of the z-component shows a strong dependence on N below a certain temperature.