R. Lyzwa et Z. Domanski, FALICOV-KIMBALL MODEL AND ITS RELATION TO THE HUBBARD-MODEL - STUDIESON CLUSTERS, Physical review. B, Condensed matter, 50(16), 1994, pp. 11381-11385
Ground-state properties of the asymmetric Hubbard model are studied on
one-dimensional clusters (rings) with N = 6, 8, and 10 sites. The gro
und-state energy, correlation functions, and phase diagrams are determ
ined for various sets of model parameters. Computations are performed
both by exact diagonalization (for N = 6) and by an approximate method
by which correlation effects can be examined on larger clusters than
exact diagonalization allows. In the Limiting cases (one limit corresp
onds to the spinless Falicov-Kimball model and the other to the Hubbar
d model) our results agree quite well with those obtained analytically
for infinite systems.