Band Degeneracy and Mott Transition: Dynamical Mean Field Study

TL;DR

This study explores the Mott transition in orbitally degenerate Hubbard models using dynamical mean field theory, revealing that qualitative features are similar to single-band models, with some quantitative differences influenced by orbital degeneracy and exchange interactions.

Contribution

It demonstrates that the qualitative behavior of the Mott transition persists in orbitally degenerate systems, supporting the use of simpler one-band models for such cases.

Findings

Qualitative features of the Mott transition are similar in degenerate and non-degenerate models.

Quantitative aspects near density one are insensitive to orbital degeneracy.

Intraatomic exchange J significantly affects certain physical quantities.

Abstract

We investigate the Mott transition in infinite dimensions in the orbitally degenerate Hubbard model. We find that the qualitative features of the Mott transition found in the one band model are also present in the orbitally degenerate case. Surprisingly, the quantitative aspects of the transition around density one are not very sensitive to orbital degeneracy, justifying the quantitative success of the one band model which was previously applied to orbitally degenerate systems. We contrast this with quantities that have a sizeable dependence on the orbital degeneracy and comment on the role of the intraatomic exchange J.