Superfluidity of a dipolar Fermi gas in 2D optical lattices bilayer

TL;DR

This paper models superfluidity in a bilayer of dipolar Fermi gases in 2D optical lattices, analyzing the transition from BCS to BEC regimes and proposing experimental conditions for observation.

Contribution

It introduces a theoretical framework for superfluidity in dipolar Fermi gases in bilayer optical lattices, including critical temperature and superfluid density calculations.

Findings

Critical temperature depends on interlayer coupling and spacing.

Superfluid density is derived using Ginzburg-Landau theory.

Crossover from BCS to BEC regimes identified via effective mass.

Abstract

We propose a model for addressing the superfluidity of two different Fermi species confined in a bilayer geometry of square optical lattices. The fermions are assumed to be molecules with interlayer s-wave interactions, whose dipole moments are oriented perpendicularly to the layers. Using functional integral techniques we investigate the BCS-like state induced in the bilayer at finite temperatures. In particular, we determine the critical temperature as a function of the coupling strength between molecules in different layers and of the interlayer spacing. By means of Ginzburg-Landau theory we calculate the superfluid density. We also study the dimerized BEC phase through the Berezinskii-Kosterlitz-Thouless transition, where the effective mass leads to identify the crossover from BCS to BEC regimes. The possibility of tuning the effective mass as a direct consequence of the lattice confinement, allows us to suggest a range of values of the interlayer spacing, which would enable observing this superfluidity within current experimental conditions.