Holographic model of superfluidity

TL;DR

This paper develops a holographic model to study superfluid phase transitions in a relativistic quantum system, revealing critical behavior, second sound dynamics, and a transition from second- to first-order as superfluid velocity increases.

Contribution

It introduces a holographic framework for superfluidity, capturing phase transition characteristics and critical phenomena in a relativistic setting.

Findings

Identifies a second-order phase transition with mean-field exponents.

Determines the second sound speed as a function of temperature.

Shows the transition becomes first-order at high superfluid velocities.

Abstract

We study a holographic model of a relativistic quantum system with a global U(1) symmetry, at non-zero temperature and density. When the temperature falls below a critical value, we find a second-order superfluid phase transition with mean-field critical exponents. In the symmetry-broken phase, we determine the speed of second sound as a function of temperature. As the velocity of the superfluid component relative to the normal component increases, the superfluid transition goes through a tricritical point and becomes first-order.