Impurity-Driven Metal-Insulator Transitions in Holography

TL;DR

This paper investigates how impurity density influences metal-insulator transitions in a holographic model, revealing that impurities can induce phase changes characterized by distinct conductivity behaviors and supported by both numerical and analytical methods.

Contribution

It introduces a holographic model where impurity density drives metal-insulator transitions, including the discovery of a quantum phase transition supported by BF bound analysis.

Findings

Impurity density can induce phase transitions in the model.

The insulating phase shows distinct temperature-dependent conductivity.

A quantum phase transition is supported by BF bound analysis.

Abstract

In this work, we study Metal-Insulator transition in a holographic model containing an interaction between the order parameter and charge-carrier density. It turns out that the impurity density of this model can drive the phase transition whose ordered phase corresponds to the insulating phase. The temperature behavior of DC conductivity distinguishes the insulating phase from the metal phase. We confirm this behavior by a numerical method and an analytic calculation. As a byproduct, we show the existence of a `quantum phase transition' supported by the Breitenlohner-Freedman bound argument.