Holographic Superconductors in a Cohesive Phase

TL;DR

This paper explores a new class of holographic superconductors within N=2 gauged supergravity, revealing rich phase structures, cohesive phases at zero temperature, and connections between scalar geometry and dual field theory deformations.

Contribution

It introduces a novel supergravity model with a topologically flat potential direction, constructing zero temperature solutions and analyzing the phase diagram and entanglement properties.

Findings

Discovery of a new class of superconducting black holes.

Identification of a cohesive phase at zero temperature.

Relation between scalar manifold geometry and dual field theory deformations.

Abstract

We consider a four-dimensional N=2 gauged supergravity coupled to matter fields. The model is obtained by a U(1) gauging of a charged hypermultiplet and therefore it is suitable for the study of holographic superconductivity. The potential has a topologically flat direction and the parameter running on this "moduli space" labels the new superconducting black holes. Zero temperature solutions are constructed and the phase diagram of the theory is studied. The model has rich dynamics. The retrograde condensate is just a special case in the new class of black holes. The calculation of the entanglement entropy makes manifest the properties of a generic solution and the superconductor at zero temperature is in a confined cohesive phase. The parameter running on the topologically flat direction is a marginal coupling in the dual field theory. We prove this statement by considering the way double trace deformations are treated in the AdS/CFT correspondence. Finally, we comment on a possible connection, in the context of gauge/gravity dualities, between the geometry of the scalar manifold in N=2 supergravity models and the space of marginal deformations of the dual field theory.