Conductivity of a strange metal: from holography to memory functions

TL;DR

This paper investigates the electrical conductivity of strange metals without quasiparticles using holography, demonstrating that the low-frequency response aligns with memory function calculations, especially when momentum relaxation is slow.

Contribution

It establishes a direct correspondence between holographic models and memory function results for conductivity in strange metals with broken translational symmetry.

Findings

Low-frequency conductivity shows a Drude peak when momentum relaxation is slow.

Relaxation time equals DC conductivity as predicted by memory functions.

Holographic and memory function approaches yield consistent results.

Abstract

We study the electrical response of a wide class of strange metal phases without quasiparticles at finite temperature and charge density, with explicitly broken translational symmetry, using holography. The low frequency electrical conductivity exhibits a Drude peak, so long as momentum relaxation is slow. The relaxation time and the direct current conductivity are exactly equal to what is computed, independently of holography, via the memory function framework.