Progress of Theoretical Physics Supplement
Decoupled Cell Monte Carlo Method for Quantum Spin Systems on Linear Chain and on Triangular Lattice
Shigeo Homma, Kazuhiro Sano, Hirotsugu Matsuda, N. Ogita
Abstract
Decoupled cell method is introduced as a method of Monte Carlo simulation for quantum spin systems. Based on this method we calculated the thermodynamic quantities such as an internal energy, in-plane and out-of-plane susceptibilities and spin-spin correlation functions in one dimensional XY model. The agreement with the exact results is excellent above a certain demarcation temperature. This method is also applied to the antiferromagnetic Heisenberg model on the triangular lattice. The results indicate the existence of a sublattice structure composed of three sublattices, although its spatial and temporal behaviours are short ranged.