The quantum Coulomb glass within the Hartree-Fock approximation

TL;DR

This paper investigates how electron-electron interactions affect the electronic properties of disordered insulators near the metal-insulator transition, focusing on the Coulomb gap and electron localization using a quantum Coulomb glass model.

Contribution

It introduces a Hartree-Fock based approach to study the quantum Coulomb glass and analyzes the impact of interactions on the Coulomb gap and localization phenomena.

Findings

Interaction enhances electron localization at the Fermi level.

Coulomb gap behavior changes near the metal-insulator transition.

Long-range interactions significantly influence electronic properties.

Abstract

We study the influence of electron-electron interactions on the electronic properties of disordered materials. In particular, we consider the insulating side of a metal-insulator transition where screening breaks down and the electron-electron interaction remains long-ranged. The investigations are based on the quantum Coulomb glass, a generalization of the classical Coulomb glass model of disordered insulators. The quantum Coulomb glass is studied by decoupling the Coulomb interaction by means of a Hartree-Fock approximation and exactly diagonalizing the remaining localization problem. We investigate the behavior of the Coulomb gap in the density of states when approaching the metal-insulator transition and study the influence of the interaction on the localization of the electrons. We find that the interaction leads to an enhancement of localization at the Fermi level.