Strongly Interacting Fermi Gases of Atoms Confined in a Harmonic Trap

TL;DR

This paper models the behavior of strongly interacting Fermi gases in harmonic traps using a combined theoretical approach, and compares predictions with recent experimental data on 6Li atoms.

Contribution

It introduces a Padé approximation-based equation of state for strongly interacting Fermi gases and applies a time-dependent local density approximation to analyze their properties.

Findings

The model accurately reproduces experimental observations.

The approach bridges weak and strong coupling regimes.

Predictions align with Monte Carlo and perturbative results.

Abstract

Dynamics of strongly interacting Fermi gases, consisting of a 50-50 mixture of two different fermionic species, is investigated. For the equation of state we consider a Pad\'{e} [2/2] approximations, which gives the weak-coupling perturbative formula (up to 4th order) in the low density regime, the unitary-limit Monte Carlo result in the high density regime, and reproduces the 4-fermion prediction for dimer-dimer scattering length in the BEC region. We use a time-dependent LDA to derive various properties of the Fermi gas under a harmonic confinement and compare them with the data of very recent experiments of 6Li atoms across a Feshbach resonance.