Complete Phase Diagrams for a Holographic Superconductor/Insulator System

TL;DR

This paper constructs the complete phase diagram of a holographic superconductor/insulator system including backreaction effects, revealing complex phase transitions and a dual Bose-Einstein condensate of glueballs.

Contribution

It extends previous work by including backreaction and mapping the full phase diagram, uncovering new transition sequences and dual gravitational descriptions.

Findings

Two phase transitions occur as temperature decreases at fixed chemical potential.

The system can transition from superconductor to insulator as temperature approaches zero.

A gravitational dual of a Bose-Einstein condensate of glueballs is constructed.

Abstract

The gravitational dual of an insulator/superconductor transition driven by increasing the chemical potential has recently been constructed. However, the system was studied in a probe limit and only a part of the phase diagram was obtained. We include the backreaction and construct the complete phase diagram for this system. For fixed chemical potential there are typically two phase transitions as the temperature is lowered. Surprisingly, for a certain range of parameters, the system first becomes a superconductor and then becomes an insulator as the temperature approaches zero. As a byproduct of our analysis, we also construct the gravitational dual of a Bose-Einstein condensate of glueballs in a confining gauge theory.