Induced interaction in a spin-polarized Fermi gas

TL;DR

This paper investigates how induced interactions influence the superfluid transition temperature and tricritical point in a spin-polarized Fermi gas, revealing significant reductions from mean-field predictions across different interaction regimes.

Contribution

It provides a detailed analysis of the induced interaction effects on superfluid transition properties in spin-polarized Fermi gases, extending beyond the BCS limit to the unitary regime.

Findings

Reduction of tricritical temperature and polarization by a factor of about 2.22 from mean-field results

In the unitary limit, polarization Pt=0.42 and transition temperature Tt/TF=0.16

Induced interactions significantly affect superfluid transition characteristics beyond the BCS limit

Abstract

We study the effect of the induced interaction on the superfluidtransition temperature of a spin-polarized Fermi gas. In the BCS limit, the polarization is very small in the superfluid state, and the effect of the induced interaction is almost the same as in the spin-balanced case. The temperature Tt and the polarization Pt of the tricritical point are both reduced from mean-field results by a factor about 2.22. This reduction is also significant beyond the BCS limit. In the unitary limit, we find (Pt,Tt/TF)=(0.42,0.16), in comparison with mean-field and experimental results.