Competition between Normal Superfluidity and Larkin-Ovchinnikov Phases of Polarized Fermi Gases in Elongated Traps

TL;DR

This paper uses the ASLDA method to study polarized Fermi gases in elongated traps, revealing coexistence of Larkin-Ovchinnikov phases with smooth superfluid states and suggesting experimental accessibility of LO phases.

Contribution

It introduces the application of ASLDA to polarized Fermi gases in elongated traps, uncovering LO solutions with transversal oscillations and contrasting previous predictions.

Findings

LO phases exhibit transversal oscillations of pairing potential

LO states coexist with smooth superfluid states

ASLDA does not support deformed superfluid cores predicted earlier

Abstract

By applying the recently proposed antisymmetric superfluid local density approximation (ASLDA) to strongly interacting polarized atomic gases at unitarity in very elongated traps, we find families of Larkin-Ovchinnikov (LO) type of solutions with prominent transversal oscillation of pairing potential. These LO states coexist with a superfluid state having a smooth pairing potential. We suggest that the LO phase could be accessible experimentally by increasing adiabatically the trap aspect ratio. We show that the local asymmetry effects contained in ASLDA do not support a deformed superfluid core predicted by previous Bogoliubov-de Gennes treatments.