Nearest-Neighbor Correlations in Hubbard Model
arXiv:cond-mat/9712023 · doi:10.1016/S0375-9601(98)00391-0
Abstract
The Hubbard Hamiltonian is investigated by means of a variational trial wave function of Gutzwiller's type. The wave function includes nearest - neighbor correlations in an explicit form. To calculate density matrices the method of Kikuchi's pseudoensemble is used. The case of half-filled fermionic band carefully investigated in the limit of a large number of lattice sites. The ground state energy and correlation functions are determined for lattices with z=2,4 and 6 nearest neighbors.
minor revisions (additional figure, fig2 is redrawn, et al.) 8 pages, 3 Post Script figures, RevTex; accepted to Phys.Lett.A