We analyze the two-orbital Hubbard model by means of the Composite Operator Method with the aim at studying the phenomenon of orbital selective Mott transition (OSMT). The model contains an interorbital interaction U′, in addition to the usual intraorbital one U. As warming-up approximation, we use a basis of two operators only, the Hubbard operators. The analysis of the density of states at the chemical potential as a function of the ratio between the bandwidths of the two orbitals shows the clear signature of an orbital selective Mott transition as expected.
@article{arxiv.0903.1544,
title = {The two-orbital Hubbard model and the OSMT},
author = {Adolfo Avella and Ferdinando Mancini and Satoru Odashima and Giovanni Scelza},
journal= {arXiv preprint arXiv:0903.1544},
year = {2015}
}