Phase Diagrams of the Two-Orbital Hubbard Model with Different Bandwidths

TL;DR

This paper studies the phase diagrams of a two-orbital Hubbard model with varying bandwidths using the self-energy functional method, highlighting the role of orbital fluctuations in Mott transitions.

Contribution

It provides a detailed phase diagram analysis for the two-orbital Hubbard model with different bandwidths, emphasizing the impact of orbital fluctuations on Mott transitions.

Findings

Orbital fluctuations significantly influence the nature of Mott transitions.

Phase diagrams differ between systems with same and different bandwidths.

The method used effectively captures the key physical phenomena.

Abstract

We investigate the two-orbital Hubbard model in infinite dimensions by means of the self-energy functional method. By calculating the entropy, susceptibility, and quasi-particle weight at zero temperature, we determine the phase diagram for the system with same and different bandwidths, which is compared with that obtained recently. It is clarified that orbital fluctuations play a key role in controlling the nature of the Mott transitions in the system.