First order metal-insulator transision in band overlap mechanism

TL;DR

This paper introduces a method to analyze the first-order metal-insulator transition caused by band overlap, utilizing a model based on the homogeneous electron gas and quasiparticle self-consistent $GW$ results.

Contribution

It presents a novel approach combining the homogeneous electron gas model with $GW$ calculations to study the band overlap-driven MIT as a first-order transition.

Findings

MIT occurs as a first-order transition with a sudden band overlap.

The method highlights the role of long-range Coulomb interactions in the transition.

Band gap becomes negative abruptly at a critical lattice constant.

Abstract

We present a method to analyze the metal-insulator transition (MIT) due to the band overlap mechanism. It is based on a model with the knowledge of the homogeneous electron gas, combined with results based on the quasiparticle self-consistent $GW$ method. Because of the long-range nature of the Coulomb interaction, the MIT occurs as the first-order phase transition, that is, the band gap becomes negative (band overlap) suddenly at some critical lattice constant.