Slave-Boson Functional-Integral Approach to the Hubbard Model with Orbital Degeneracy
نویسنده
چکیده
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, whose paramagnetic state has been studied by numerical calculations. The effect of the exchange interaction on the metalinsulator (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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