A Novel Mechanism to Generate FFLO States in Holographic Superconductors

TL;DR

This paper introduces a new holographic model for FFLO states in strongly coupled superconductors, using two gauge fields and a scalar to simulate inhomogeneous pairing phenomena at low temperatures.

Contribution

It proposes a novel gravitational mechanism involving Einstein tensor coupling to generate FFLO states in holographic superconductors.

Findings

Inhomogeneous solutions have higher critical temperatures than homogeneous ones.

The model successfully captures FFLO state characteristics in a holographic framework.

The mechanism links scalar coupling to Einstein tensor with inhomogeneous superconducting phases.

Abstract

We discuss a novel mechanism to set up a gravity dual of FFLO states in strongly coupled superconductors. The gravitational theory utilizes two U(1) gauge fields and a scalar field coupled to a charged AdS black hole. The first gauge field couples with the scalar sourcing a charge condensate below a critical temperature, and the second gauge field provides a coupling to spin in the boundary theory. The scalar is neutral under the second gauge field. By turning on an interaction between the Einstein tensor and the scalar, it is shown that, in the low temperature limit, an inhomogeneous solution possesses a higher critical temperature than the homogeneous case, giving rise to FFLO states.