Superfluid shells for trapped fermions with mass and population imbalance

TL;DR

This paper explores the phase diagram of strongly interacting trapped fermions with mass and population imbalance, revealing a unique superfluid shell structure with distinct normal regions, and proposes density profiles as experimental signatures.

Contribution

It introduces the concept of superfluid shells in imbalanced fermion systems and maps their phase diagram, highlighting differences from equal-mass cases.

Findings

Superfluid forms a non-simply connected shell structure.

Normal states occupy regions inside and outside the superfluid shell.

Density profiles can serve as experimental signatures.

Abstract

We map out the phase diagram of strongly interacting fermions in a potential trap with mass and population imbalance between the two spin components. As a unique feature distinctively different from the equal-mass case, we show that the superfluid here forms a shell structure which is not simply connected in space. Different types of normal states occupy the trap regions inside and outside this superfluid shell. We calculate the atomic density profiles, which provide an experimental signature for the superfluid shell structure.