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Generalization of the iterative perturbation theory and metal-insulator transition in multi-orbital Hubbard bands

Takeo Fujiwara·Susumu Yamamoto·Yasushi Ishii
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Abstract

The iterative perturbation theory of the dynamical mean field theory is generalized to arbitrary electron occupation in case of multi-orbital Hubbard bands. We present numerical results of doubly degenerate Eg bands in a simple cubic lattice. The spectrum shows the electron ionization and affinity levels of different electron occupations. For sufficiently large Coulomb integral, a gap opens in the spectrum at integer filling of electrons and the system becomes insulator. The present scheme is easy to combine with the LSDA electronic structure theory.

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Takeo Fujiwara, Susumu Yamamoto, Yasushi Ishii. 2002-11-08. Generalization of the iterative perturbation theory and metal-insulator transition in multi-orbital Hubbard bands. https://doi.org/10.1143/jpsj.72.777

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