@incollection{statphys23_0627,
title = {Exact ground-state results for the two-orbital Hubbard model at half filling},
address = {Genova, Italy},
author = {M.E. Amendola and C. Noce and A. Romano},
booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics},
editor = {Luciano Pietronero and Vittorio Loreto and Stefano Zapperi},
month = {9-13 July},
url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=627},
year = {2007},
abstract = {Exact inequalities between the relevant excitation gaps are derived
for the orbitally degenerate Hubbard model. Applying a generalized version
of the Lieb's spin-reflection positivity method, it is shown that in the
case of half-filling the charge gap is always larger of both the spin
excitation gap and the orbital gap, this latter corresponding to the
difference in energy of the ground states having orbital quantum numbers
differing by one. These exact results are illustrated through the explicit
evaluation of the excitation gaps, performed via the diagonalization of the
model on small finite-size clusters.},
keywords = {correlated excitation fermions gaps hubbard model statphys23 strongly topic-8 two-orbital }
}
::