Scaling of the Holographic AC conductivity for non-Fermi liquids at criticality

Understand

The frequency dependence of the AC conductivity is studied in a holographic model of a non-fermi liquid that is amenable to both analytical and numerical computation.

• In the regime that dissipation dominates the DC conductivity, the AC conductivity is described well in the IR by a Drude peak despite the absence of quasiparticles.
• In the regime where pair-production-like processes dominate the conductivity there is no Drude peak.
• A scaling tail is found for the AC conductivity that is independent of the charge density and momentum dissipation.