Insulator-metal-insulator transition and selective spectral weight transfer in a disordered strongly correlated system

TL;DR

This paper studies how disorder and electron interactions cause insulator-metal-insulator transitions in a correlated system, revealing spectral weight transfer and temperature effects using advanced theoretical methods.

Contribution

It introduces a detailed analysis of metal-insulator transitions in a disordered Hubbard model with novel insights into spectral weight transfer and temperature dependence.

Findings

Two successive metal-insulator transitions at integer fillings.

Selective spectral weight transfer upon doping.

Strong temperature influence on low energy dynamics.

Abstract

We investigate the metal insulator transitions at finite temperature for the Hubbard model with diagonal alloy disorder. We solve the dynamical mean field theory equations with the non crossing approximation and we use the coherent potential approximation to handle disorder. The excitation spectrum is given for various correlation strength $U$ and disorder. Two successive metal insulator transitions are observed at integer filling values as $U$ is increased. An important selective transfer of spectral weight arises upon doping. The strong influence of the temperature on the low energy dynamics is studied in details.