Strongly-resonant p-wave superfluids

TL;DR

This paper theoretically investigates p-wave superfluids in a dilute fermionic gas, revealing two regimes and an instability towards triplet formation, with implications for experimental realization.

Contribution

It identifies and characterizes weak and strong p-wave resonant superfluid regimes and uncovers an instability leading to triplet formation.

Findings

Strongly-resonant p-wave superfluids are unstable to triplet formation.

The lifetime of p-wave molecules is limited by collisional relaxation.

Distinct behaviors are predicted for weak and strong resonance regimes.

Abstract

We study theoretically a dilute gas of identical fermions interacting via a p-wave resonance. We show that, depending on the microscopic physics, there are two distinct regimes of p-wave resonant superfluids, which we term "weak" and "strong". Although expected naively to form a BCS-BEC superfluid, a strongly-resonant p-wave superfluid is in fact unstable towards the formation of a gas of fermionic triplets. We examine this instability and estimate the lifetime of the p-wave molecules due to the collisional relaxation into triplets. We discuss consequences for the experimental achievement of p-wave superfluids in both weakly- and strongly-resonant regimes.