Optical Conductivity with Holographic Lattices

TL;DR

This paper introduces a gravitational lattice into a holographic model to study optical conductivity, revealing finite DC conductivity and Drude-like behavior, which resemble properties observed in cuprate superconductors.

Contribution

The study incorporates a gravitational lattice into holographic models, demonstrating how it affects optical conductivity and mimics experimental features of cuprates.

Findings

Zero frequency delta function is broadened with lattice inclusion.

DC conductivity becomes finite due to lattice effects.

Optical conductivity shows a Drude peak and power-law behavior.

Abstract

We add a gravitational background lattice to the simplest holographic model of matter at finite density and calculate the optical conductivity. With the lattice, the zero frequency delta function found in previous calculations (resulting from translation invariance) is broadened and the DC conductivity is finite. The optical conductivity exhibits a Drude peak with a cross-over to power-law behavior at higher frequencies. Surprisingly, these results bear a strong resemblance to the properties of some of the cuprates.