Superconductivity in the two-band Hubbard model

TL;DR

This paper investigates the emergence of s-wave superconductivity in a two-band Hubbard model using dynamical mean-field theory, revealing how repulsive interactions can lead to superconducting states and their competition with other phases.

Contribution

It demonstrates the stabilization of s-wave superconductivity in a repulsive two-band Hubbard model using advanced quantum Monte Carlo methods, considering Hund coupling and crystal field effects.

Findings

Superconductivity can occur in the repulsive two-band Hubbard model.

Superconducting state competes with metallic and Mott phases.

Hund coupling and crystal field influence phase stability.

Abstract

We study the two-band Hubbard model in infinite dimensions by solving the dynamical mean-field equations with a strong coupling continuous-time quantum Monte Carlo method and show that an $s$-wave superconducting state can be stabilized in the repulsively interacting case. We discuss how this superconducting state competes with the metallic and paired Mott states. The effects of the Hund coupling and crystalline electric field are also addressed.