# Critical transport and vortex dynamics in a thin atomic Josephson junction

## TL;DR

This paper investigates how vortex ring nucleation causes dissipation in a thin atomic Josephson junction between Fermi superfluids, linking microscopic vortex dynamics to macroscopic transport properties.

## Contribution

It provides a detailed simulation-based analysis of vortex ring nucleation and its role in dissipation, aligning with experimental observations and elucidating the microscopic mechanisms.

## Key findings

- Identification of critical population imbalance and maximum Josephson current for dissipation onset.
- Demonstration that quantum phase slips via vortex rings cause resistive current.
- Quantitative agreement with experimental data on vortex dynamics and transport.

## Abstract

We study the onset of dissipation in an atomic Josephson junction between Fermi superfluids in the molecular Bose-Einstein condensation limit of strong attraction. Our simulations identify the critical population imbalance and the maximum Josephson current delimiting dissipationless and dissipative transport, in quantitative agreement with recent experiments. We unambiguously link dissipation to vortex ring nucleation and dynamics, demonstrating that quantum phase slips are responsible for the observed resistive current. Our work directly connects microscopic features with macroscopic dissipative transport, providing a comprehensive description of vortex ring dynamics in three-dimensional inhomogeneous constricted superfluids at zero and finite temperatures.