Dynamical mean-field approximation for unitary Fermi gas

TL;DR

This paper applies a dynamical mean-field approximation to study a unitary Fermi gas, revealing good agreement with Monte Carlo results at zero temperature and identifying a second order phase transition at finite temperature.

Contribution

It introduces a dynamical mean-field approach with explicit pairing for the unitary Fermi gas, bridging lattice and continuum models, and explores finite temperature phase transitions.

Findings

Zero temperature energy and pairing gap match Monte Carlo results

Identifies a second order phase transition with heat capacity jump

Observes collapse of pairing gap at transition

Abstract

Dynamical mean-field approximation with explicit pairing is utilized to study the properties of a two-component Fermi gas at unitarity. The problem is approximated by the lattice Hubbard Hamiltonian, and the continuum limit is realized by diluting the lattice. We have found that at zero temperature the predictions of this theory for the energy and the pairing gap agree remarkably well with the results of full numerical Monte-Carlo simulations. Investigating the evolution of the system with temperature we identify the existence of a second order phase transition associated with a jump in the heat capacity and the collapse of the pairing gap.