Exploring Exotic Superfluidity of Polarized Ultracold Fermions in Optical Lattices

TL;DR

This paper theoretically investigates the novel superfluid phases of polarized ultracold fermions in 2D optical lattices, predicting oscillating pairing amplitudes and a new FFLO state, with implications for experimental verification.

Contribution

It introduces a theoretical prediction of a new FFLO superfluid state in polarized ultracold fermions in optical lattices, expanding understanding of exotic superfluidity.

Findings

Pairing amplitude oscillates radially at low density.

Pairing amplitude oscillates angularly at high density.

Predicted a new FFLO superfluid state for experimental testing.

Abstract

We explore theoretically the novel superfluidity of harmonically-trapped polarized ultracold fermionic atoms in a two-dimensional (2D) optical lattice by solving the Bogoliubov-de Gennes equations. The pairing amplitude is found to oscillate along the radial direction at low particle density and along the angular direction at high density. The former is consistent with the existing experiments and the latter is a newly predicted Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, which can be tested in experiments.