Mott-Hubbard insulators for systems with orbital degeneracy.

Gunnarsson O., Koch E., Martin R.M.

Max-Planck-Institut für Festkörperforschung, Stuttgart; Department of Physics, University of Illinois, Urbana-Champaign}, abstract = {We study how the electron hopping reduces the Mott-Hubbard band gap in the limit of a large Coulomb interaction U and as a function of the orbital degeneracy N. The results support the conclusion that the hopping contribution grows as roughly square root NW, where W is the one-particle bandwidth, but in certain models a crossover to an NW behavior is found for sufficiently large N.

A reprint of this paper can be obtained from cond-mat in Germany or in the US.

Physical Review B, 56 1146-52, 1997.

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