GUTZWILLER APPROXIMATION IN DEGENERATE HUBBARD MODELS

We obtain exact numerical solutions of the degenerate Hubbard model in the limit of large dimensions (or large lattice connectivity). Successive Mott-Hubbard metal insulator transitions at integer fillings occur at intermediate values of the interaction and low enough temperature in the paramagnetic phase. The results are relevant for transition metal oxides with partially filled narrow degenerate bands.

arXiv:cond-mat/9611045Physical review. B, Condensed matterFeb 15, 1997147 citations

Slave-Boson Functional-Integral Approach to the Hubbard Model with Orbital Degeneracy

Hideo Hasegawa

arXiv:cond-mat/9612142Journal of the Physical Society of JapanMay 15, 199738 citations

GUTZWILLER APPROXIMATION IN DEGENERATE HUBBARD MODELS

Jian Ping Lu

Published Aug 14, 2021• 0 citations

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Abstract

DOI: 10.17615/brvt-a480

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A slave-boson functional-integral method has been developed for the Hubbard model with arbitrary, orbital degeneracy

D

. Its saddle-point mean-field theory is equivalent to the Gutzwiller approximation, as in the case of single-band Hubbard model. Our theory is applied to the doubly degenerate (

D = 2

) model, and numerical calculations have been performed for this model in the paramagnetic states. The effect of the exchange interaction on the metal-insulator (MI) transition is discussed. The critical interaction for the MI transition is analytically calculated as functions of orbital degeneracy and electron occupancy.