Josephson oscillation of a superfluid Fermi gas

TL;DR

This paper investigates Josephson oscillations in a superfluid Fermi gas using numerical simulations, revealing how oscillation frequency depends on optical lattice strength and identifying conditions for breakdown of oscillations.

Contribution

It provides a detailed numerical analysis of Josephson oscillations in a superfluid Fermi gas, extending understanding from Bose-Einstein condensates to Fermi systems.

Findings

Josephson frequency decreases with increasing optical lattice strength

Breakdown of Josephson oscillation occurs at large trap displacements

Results align with experimental observations for Bose-Einstein condensates and ideal Fermi gases

Abstract

Using the complete numerical solution of a time-dependent three-dimensional mean-field model we study the Josephson oscillation of a superfluid Fermi gas (SFG) at zero temperature formed in a combined axially-symmetric harmonic plus one-dimensional periodic optical-lattice (OL) potentials after displacing the harmonic trap along the axial OL axis. We study the dependence of Josephson frequency on the strength of the OL potential. The Josephson frequency decreases with increasing strength as found in the experiment of Cataliotti et al. [Science 293 (2001) 843] for a Bose-Einstein condensate and of the experiment of Pezze et al. [Phys. Rev. Lett. 93 (2004) 120401] for an ideal Fermi gas. We demonstrate a breakdown of Josephson oscillation in the SFG for a large displacement of the harmonic trap. These features of Josephson oscillation of a SFG can be tested experimentally.