M. Distasio et al., THE EFFECTS OF QUANTUM FLUCTUATIONS IN THE LARGE-U HUBBARD-MODEL AT HALF-FILLING, Journal of physics. Condensed matter, 6(6), 1994, pp. 53-58
A quantitative estimate of the role of quantum fluctuations is given a
t zero and finite temperatures within the one-loop approximation aroun
d the antiferromagnetic and dimer saddle points. Our results include t
he constraint of single occupancy of sites, also for thermodynamical q
uantities.