Holographic Superconductors in a Non-minimally Coupled Einstein-Maxwell-scalar Model

TL;DR

This paper explores holographic superconductors within a non-minimally coupled Einstein-Maxwell-scalar framework, revealing how coupling affects critical temperature, condensate behavior, and optical conductivity features like gap formation and low-temperature spikes.

Contribution

It introduces a non-minimal coupling in holographic superconductor models and analyzes its effects on critical temperature, condensate, and optical conductivity.

Findings

Critical temperature increases with coupling constant .

Scalar condensate decreases as  increases.

A low-temperature spike appears in the optical conductivity gap.

Abstract

In this paper, we investigate holographic superconductors dual to asymptotically anti-de Sitter black holes in an Einstein-Maxwell-scalar model with a non-minimal coupling between the scalar and Maxwell fields. In the probe limit, it shows that the scalar condensate occurs below the critical temperature $T_{c}$, and decreases with the increase of the coupling constant $\alpha$. On the other hand, the the critical temperature $T_{c}$ increases as the coupling constant $\alpha$ grows. We also calculate the optical conductivity of the holographic superconductor, and observe that a gap forms below $T_{c}$. Interestingly, the non-minimal coupling can lead to a spike occurring in the gap at a low temperature.