Physical review. B, Condensed matter
High-temperature series expansions for the Hubbard model
D. F. B. ten Haaf, J. M. J. van Leeuwen
Abstract
A method is described to obtain high-temperature series expansions for the grand potential and the nearest-neighbor correlation of the z-component of the spin in the Hubbard model. The method is applied to the square and simple cubic lattices. The series have been calculated up to eighth order in \ensuremath{\beta}t. The convergence of the series is discussed and a comparison with previous results in the literature is made. The present calculations contain an indication for the occurrence of a Nagaoka-like phase.