Correlation Induced Insulator to Metal Transitions

TL;DR

This paper investigates a spinless two-band model in infinite dimensions, revealing transitions from a band insulator to metallic and charge-Mott insulator phases, with the metallic phase exhibiting non-Fermi liquid behavior.

Contribution

It introduces a comprehensive analysis of phase transitions in a two-band model using multiple methods, highlighting the non-Fermi liquid nature of the metallic phase.

Findings

Identified insulator-to-metal and insulator-to-charge-Mott insulator transitions.

Discovered the metallic phase as a non-Fermi liquid with universal algebraic correlations.

Used a combination of analytical, Quantum Monte Carlo, and recursion methods.

Abstract

We study a spinless two-band model at half-filling in the limit of infinite dimensions. The ground state of this model in the non-interacting limit is a band-insulator. We identify transitions to a metal and to a charge-Mott insulator, using a combination of analytical, Quantum Monte Carlo, and zero temperature recursion methods. The metallic phase is a non-Fermi liquid state with algebraic local correlation functions with universal exponents over a range of parameters.