Topological transition from superuid vortex rings to isolated knots and links

TL;DR

This paper introduces a method to generate and control topological vortex knots and links in superfluids, revealing new helicity transfer phenomena and stability enhancements through initial state design.

Contribution

It presents a novel scheme for creating and manipulating vortex knots and links in Bose-Einstein condensates, including control over topology transitions and stability improvements.

Findings

Helicity transfer between knots/links and coils occurs bidirectionally.

Topology transition pathways can be controlled via initial states.

Knots and links stability can be significantly enhanced.

Abstract

Knots and links are fundamental topological objects play a key role in both classical and quantum fluids. In this research, we propose a novel scheme to generate torus vortex knots and links through the reconnections of vortex rings perturbed by Kelvin waves in trapped Bose-Einstein condensates. We observe a new phenomenon in a confined superfluid system in which the transfer of helicity between knots/links and coils can occur in both directions with different pathways. The pathways of topology transition can be controlled through designing specific initial states. The generation of a knot or link can be achieved by setting the parity of the Kelvin wave number. The stability of knots/links can be improved greatly with tunable parameters, including the ideal relative angle and the minimal distance between the initial vortex rings.