Metallic AdS/CFT

TL;DR

This paper employs the AdS/CFT correspondence to calculate the electrical conductivity of massive hypermultiplet fields in a strongly coupled plasma, revealing consistent results across various parameters and extending to drag force analysis.

Contribution

It provides a comprehensive calculation of conductivity at finite density and mass in N=4 SYM using holography, including the drag force on charge carriers, with a method applicable to diverse probe brane systems.

Findings

Conductivity results are valid across all mass, field, and density values.

At large mass, the drag force matches the zero-density case.

The approach generalizes to various probe brane configurations.

Abstract

We use the AdS/CFT correspondence to compute the conductivity of massive N=2 hypermultiplet fields at finite baryon number density in an N=4 SU(N_c) super-Yang-Mills theory plasma in the large N_c, large 't Hooft coupling limit. The finite baryon density provides charge carriers analogous to electrons in a metal. An external electric field then induces a finite current which we determine directly. Our result for the conductivity is good for all values of the mass, external field and density, modulo statements about the yet-incomplete phase diagram. In the appropriate limits it agrees with known results obtained from analyzing small fluctuations around equilibrium. For large mass, where we expect a good quasi-particle description, we compute the drag force on the charge carriers and find that the answer is unchanged from the zero density case. Our method easily generalizes to a wide class of systems of probe branes in various backgrounds.