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

Hideo Hasegawa
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Abstract

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.

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Hideo Hasegawa. 1997-06-10. Slave-Boson Functional-Integral Approach to the Hubbard Model with Orbital Degeneracy. https://doi.org/10.1143/jpsj.66.1391

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