Effects of orbital degeneracy on the Mott transition in infinite dimensions

Abstract

We investigate the Mott transition in infinite dimensions in the orbitally degenerate Hubbard model. The qualitative features of the Mott transition found in the one-band model are also present in the orbitally degenerate case. We show that the quantitative aspects of the low-energy behavior near the Mott insulating state with one electron per site are not very sensitive to orbital degeneracy, justifying the quantitative success of the one-band model which had been previously applied to orbitally degenerate systems. We contrast this with quantities that have a sizable dependence on the orbital degeneracy and comment on the role of the intra-atomic exchange J. \textcopyright{} 1996 The American Physical Society.