Controlled Transport between Fermi Superfluids Through a Quantum Point Contact

TL;DR

This paper explores the transport phenomena between two Fermi superfluids connected via a quantum point contact, revealing multiple regimes like Andreev reflection, self-trapping, and Josephson oscillations, with potential experimental verification.

Contribution

It introduces a unified setup capable of realizing and analyzing three distinct charge transport behaviors in Fermi superfluids, highlighting the crossover dynamics.

Findings

Identification of three transport regimes: Andreev reflection, self-trapping, Josephson oscillation.

Analysis of atom number difference dynamics under various conditions.

Potential for experimental verification in current cold atomic gas systems.

Abstract

Recent advances in experimental techniques allow one to create a quantum point contact between two Fermi superfluids in cold atomic gases with a tunable transmission coefficient. In this Letter we propose that three distinct behaviors of charge transports between two Fermi superfluids can be realized in this single setup, which are the multiple Andreev reflection, the self-trapping and the Josephson oscillation. We investigate the dynamics of atom number difference between two reservoirs for different initial conditions and different transmission coefficients, and present a coherent picture of how the crossover between different regimes takes place. Our results can now be directly verified in current experimental system.