Superfluid to insulator phase transition in a unitary Fermi gas

TL;DR

This paper investigates the superfluid to insulator phase transition in a unitary Fermi gas by modeling it with the Hubbard Hamiltonian and analyzing the temperature dependence of the energy gap.

Contribution

It introduces a lattice model approach and dynamical mean-field approximation to study the phase transition in a unitary Fermi gas.

Findings

Below Tc, the system is superfluid with decreasing energy gap.

Above Tc, the system becomes an insulator with increasing energy gap.

The energy gap behavior distinctly characterizes the phase transition.

Abstract

We study the evolution of the energy gap in a unitary Fermi gas as a function of temperature. To this end we approximate the Fermi gas by the Hubbard lattice Hamiltonian and solve using the dynamical mean-field approximation. We have found that below the critical temperature, Tc, the system is a superfluid and the energy gap is decreasing monotonously. For temperatures above Tc the system is an insulator and the corresponding energy gap is monotonously increasing.