arXiv:cond-mat/0206033 · Journal of the Physical Society of Japan
Off-Diagonal Wave Function Monte Carlo Studies of Hubbard Model I
Takashi Yanagisawa, Soh Koike, Yamaji K.
Abstract
We propose a Monte Carlo method, which is a hybrid method of the quantum Monte Carlo method and variational Monte Carlo theory, to study the Hubbard model. The theory is based on the off-diagonal and the Gutzwiller type correlation factors which are taken into account by a Monte Carlo algorithm. In the 4x4 system our method is able to reproduce the exact results obtained by the diagonalization. An application is given to investigate the half-filled band case of two-dimensional square lattice. The energy is favorably compared with quantum Monte Carlo data.