A Simple Holographic Insulator

TL;DR

This paper introduces a straightforward holographic insulator model with a nonsingular zero-temperature geometry, demonstrating power-law conductivities and a transition to a conductor with a Drude peak upon parameter variation.

Contribution

The model is simpler and features a nonsingular IR geometry, differing from previous holographic insulators, and captures the insulator-conductor transition.

Findings

Zero temperature IR geometry is nonsingular.

Both DC and optical conductivities follow the same power law.

Parameter change induces insulator-to-conductor transition with Drude peak.

Abstract

We present a simple holographic model of an insulator. Unlike most previous holographic insulators, the zero temperature infrared geometry is completely nonsingular. Both the low temperature DC conductivity and the optical conductivity at zero temperature satisfy power laws with the same exponent, given by the scaling dimension of an operator in the IR. Changing a parameter in the model converts it from an insulator to a conductor with a standard Drude peak.