Integer filling metal insulator transitions in the degenerate Hubbard model

TL;DR

This paper provides exact numerical solutions for the degenerate Hubbard model in high dimensions, revealing multiple Mott-Hubbard metal-insulator transitions at specific fillings and interaction strengths, relevant for transition metal oxides.

Contribution

It offers the first exact numerical analysis of the degenerate Hubbard model in the large dimension limit, highlighting multiple transitions at integer fillings.

Findings

Multiple Mott-Hubbard transitions occur at intermediate interactions.

Transitions happen at low temperatures in the paramagnetic phase.

Results are applicable to transition metal oxides with degenerate bands.

Abstract

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.