Resonant pairing between Fermions with unequal masses

TL;DR

This paper investigates the pairing behavior of Fermions with different masses at unitarity, revealing how mass imbalance affects phase separation and density profiles in trapped systems.

Contribution

It provides new insights into how mass imbalance influences pairing, phase separation, and density distributions in Fermionic systems at unitarity.

Findings

Equal populations show thermodynamic properties similar to equal mass case after rescaling.

Light majority species prevent phase separation at unequal populations.

Heavy majority species lead to phase separation with higher normal phase density.

Abstract

We study the pairing between Fermions of different masses, especially at the unitary limit. At equal populations, the thermodynamic properties are identical with the equal mass case provided an appropriate rescaling is made. At unequal populations, for sufficiently light majority species, the system does not phase separate. For sufficiently heavy majority species, the phase separated normal phase have a density larger than that of the superfluid. For atoms in harmonic traps, the density profiles for unequal mass Fermions can be drastically different from their equal-mass counterparts.