Controlled generation of 3D vortices in driven atomic Josephson junctions

TL;DR

This paper introduces a method to generate and control three-dimensional solitary waves, including vortex rings and rarefaction pulses, in atomic Josephson junctions using an ac-driven protocol, enabling detailed studies of vortex dynamics.

Contribution

It presents a novel ac-driven atomic Josephson junction setup that deterministically produces and controls 3D solitonic excitations, bridging vortex rings and rarefaction pulses.

Findings

Controlled emission of single and multiple solitons per drive cycle.

Observation of leapfrogging dynamics of coaxial vortex rings.

Platform for studying nonlinear vortex behavior and quantum turbulence.

Abstract

We propose an ac-driven atomic Josephson junction as a clean and tunable source of three dimensional (3D) solitary waves in quantum fluids. Depending on the height of the junction barrier, the emitted excitations appear as vortex rings at low velocity or vorticity-free rarefaction pulses near the sound velocity, thus spanning the complete Jones-Roberts family of solitons. The Shapiro-step phenomenon renders the emission deterministic: on the first, second, third Shapiro steps, the junction ejects one, two, and three solitary excitations per drive cycle. This enables controlled generation of single- and multi-excitation configurations, allowing detailed studies of the full crossover between vortex rings and rarefaction pulses and their interaction dynamics. In particular, deterministic multi-ring emission provides insights into leapfrogging dynamics of two and three coaxial rings and their decay via boundary-assisted, sound-mediated processes. This ac-driven protocol establishes a compact and reproducible platform for generating, classifying, and controlling 3D solitonic excitations, paving the way for precision studies of nonlinear vortex dynamics, dissipation, and quantum turbulence in trapped superfluids.