Refractive index in holographic superconductors

TL;DR

This paper studies the optical properties of s-wave holographic superconductors in the probe limit, revealing that they do not exhibit negative phase velocity at low frequencies due to their permittivity and permeability behavior.

Contribution

It provides the first analysis of electric permittivity and magnetic permeability in holographic superconductors, showing their limitations in achieving negative phase velocity.

Findings

Electric permittivity and magnetic permeability do not lead to negative Depine-Lakhtakia index at low frequencies.

Negative phase velocity does not occur in these holographic superconductors under the studied conditions.

Optical properties differ from those in strongly coupled systems with gravity duals of charged black holes.

Abstract

With the probe limit, we investigate the behavior of the electric permittivity and effective magnetic permeability and related optical properties in the s-wave holographic superconductors. In particular, our result shows that unlike the strong coupled systems which admit a gravity dual of charged black holes in the bulk, the electric permittivity and effective magnetic permeability are unable to conspire to bring about the negative Depine-Lakhtakia index at low frequencies, which implies that the negative phase velocity does not appear in the holographic superconductors under such a situation.