A criterion for the nature of the superconducting transition in strongly interacting field theories : Holographic approach

TL;DR

This paper uses holographic duality to establish a criterion for determining whether superconducting phase transitions are first or second order in strongly interacting theories, based on vortex interactions.

Contribution

It introduces a holographic criterion for the nature of superconducting transitions, identifying tricritical points via vortex interactions and effective parameters.

Findings

Identification of tricritical points in chemical potential and Ginzburg-Landau parameter

Vortex interactions determine the order of phase transition

First order transition linked to Coleman-Weinberg mechanism

Abstract

It is beyond the present techniques based on perturbation theory to reveal the nature of phase transitions in strongly interacting field theories. Recently, the holographic approach has provided us with an effective dual description, mapping strongly coupled conformal field theories to classical gravity theories. Resorting to the holographic superconductor model, we propose a general criterion for the nature of the superconducting phase transition based on effective interactions between vortices. We find "tricritical" points in terms of the chemical potential for U(1) charges and an effective Ginzburg-Landau parameter, where vortices do not interact to separate the second order (repulsive) from the first order (attractive) transitions. We interpret the first order transition as the Coleman-Weinberg mechanism, arguing that it is relevant to superconducting instabilities around quantum criticality.