Universal phase diagram of a strongly interacting Fermi gas with unbalanced spin populations

TL;DR

This paper provides a theoretical framework to interpret experimental results on strongly interacting Fermi gases with unbalanced spins, identifying phase boundaries through dimensionless parameters and refining their bounds.

Contribution

It introduces a universal phase diagram for strongly interacting Fermi gases with spin imbalance, using a variational approach and experimental data to define key parameters.

Findings

Boundaries of three phases characterized by two dimensionless numbers

Precise bounds for the parameters η_α and η_β

Unified interpretation of experimental density profiles

Abstract

We present a theoretical interpretation of a recent experiment presented in ref. \cite{Zwierlein06} on the density profile of Fermi gases with unbalanced spin populations. We show that in the regime of strong interaction, the boundaries of the three phases observed in \cite{Zwierlein06} can be characterized by two dimensionless numbers $\eta\_\alpha$ and $\eta\_\beta$. Using a combination of a variational treatment and a study of the experimental results, we infer rather precise bounds for these two parameters.