Incoherent conductivity of holographic charge density waves

TL;DR

This paper calculates the incoherent conductivity in holographic charge density waves with spontaneous translation breaking, revealing that resistivity is governed by diffusive processes rather than momentum relaxation.

Contribution

It introduces a holographic computation of incoherent conductivity in spatially modulated charge density waves with spontaneous translation symmetry breaking.

Findings

Incoherent conductivity is computed in the zero disorder limit.

The boundary heat current is derived from a conserved bulk current.

Diffusive processes dominate resistivity over momentum relaxation.

Abstract

The DC resistivity of charge density waves weakly-pinned by disorder is controlled by diffusive, incoherent processes rather than slow momentum relaxation. The corresponding incoherent conductivity can be computed in the limit of zero disorder. We compute this transport coefficient in holographic spatially modulated breaking translations spontaneously. As a by-product of our analysis, we clarify how the boundary heat current is obtained from a conserved bulk current, defined as a suitable generalization of the Iyer-Wald Noether current of the appropriate Killing vector.