Mixing-demixing in a trapped degenerate fermion-fermion mixture

TL;DR

This paper models and analyzes how increasing interspecies repulsion and trap frequencies can induce a transition from mixed to demixed states in a degenerate fermion-fermion mixture, with potential experimental realizations.

Contribution

It introduces a dynamical mean-field-hydrodynamic model to study mixing-demixing transitions in fermion-fermion mixtures under various trapping conditions.

Findings

Increased interspecies repulsion leads to demixing.

Higher trap frequencies promote phase separation.

Demixed states are experimentally achievable near Feshbach resonances.

Abstract

We use a time-dependent dynamical mean-field-hydrodynamic model to study mixing-demixing in a degenerate fermion-fermion mixture (DFFM). It is demonstrated that with the increase of interspecies repulsion and/or trapping frequencies, a mixed state of DFFM could turn into a fully demixed state in both three-dimensional spherically-symmetric as well as quasi-one-dimensional configurations. Such a demixed state of a DFFM could be experimentally realized by varying an external magnetic field near a fermion-fermion Feshbach resonance, which will result in an increase of interspecies fermion-fermion repulsion, and/or by increasing the external trap frequencies.