Mass-imbalance induced metal-insulator transition in a three-component Hubbard model

TL;DR

This study investigates how mass imbalance influences the metal-insulator transition in a three-component Hubbard model, revealing a species-selective transition driven by mass differences under specific conditions.

Contribution

It introduces a detailed analysis of mass imbalance effects on metal-insulator transitions using dynamical mean-field theory in a three-component fermionic system.

Findings

Mass imbalance can induce a metal-insulator transition.

The transition is species-selective for lighter particles.

Transition occurs at commensurate densities and moderate interactions.

Abstract

The effects of mass imbalance in a three-component Hubbard model are studied by the dynamical mean-field theory combined with exact diagonalization. The model describes a fermion-fermion mixture of two different particle species with a mass imbalance. One species is two-component fermion particles, and the other is single-component ones. The local interaction between particle species is considered isotropically. It is found that the mass imbalance can drive the mixture from insulator to metal. The insulator-metal transition is a species-selective-like transition of lighter mass particles and occurs only at commensurate particle densities and moderate local interactions. For weak and strong local interactions the mass imbalance does not change the ground state of the mixture.