Anderson localization effects on doped Hubbard model

TL;DR

This paper maps out the phase diagram of the doped Hubbard model, revealing how disorder and doping induce transitions between metallic and insulating states, including Mott and Anderson insulators, using advanced theoretical methods.

Contribution

It combines Dynamical Mean Field Theory with Typical Medium Theory to systematically study disorder and doping effects in the Hubbard model, identifying new phases and transition behaviors.

Findings

Transition from metal to Anderson-Mott insulator with increasing disorder.

Presence of empty sites in the weak correlation, low doping Anderson-Mott insulator.

Emergence of a different Anderson-Mott phase at higher doping or correlation, lacking empty sites.

Abstract

We derive the disorder vs. doping phase diagram of the doped Hubbard model via Dynamical Mean Field Theory combined with Typical Medium Theory, which allows the description of both Mott (correlation driven) and Anderson (disorder driven) metal-insulator transitions. We observe a transition from a metal to an Anderson-Mott insulator for increasing disorder strength at all interactions. In the weak correlation regime and rather small doping, the Anderson-Mott insulator displays properties which are alike to the ones found at half-filling. In particular, this phase is characterized by the presence of empty sites. If we further increase either the doping or the correlation however, an Anderson-Mott phase of different kind arises for sharply weaker disorder strength. This phase occupies the largest part of the phase diagram in the strong correlation regime, and is characterized by the absence of the empty sites.