%0 Book Section %1 statphys23_0627 %A Amendola, M.E. %A Noce, C. %A Romano, A. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K correlated excitation fermions gaps hubbard model statphys23 strongly topic-8 two-orbital %T Exact ground-state results for the two-orbital Hubbard model at half filling %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=627 %X 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.

@incollection{statphys23_0627, 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.}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Amendola, M.E. and Noce, C. and Romano, A.}, biburl = {https://www.bibsonomy.org/bibtex/202948917be99fc6b0e53cbfb65a18972/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {606bb6801d81da0c3097bafd3b455819}, intrahash = {02948917be99fc6b0e53cbfb65a18972}, keywords = {correlated excitation fermions gaps hubbard model statphys23 strongly topic-8 two-orbital}, month = {9-13 July}, timestamp = {2007-06-20T10:16:25.000+0200}, title = {Exact ground-state results for the two-orbital Hubbard model at half filling}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=627}, year = 2007 }