Coherent vortex structures in quantum turbulence

TL;DR

This paper demonstrates that in intense quantum turbulence, bundles of quantized vortices form coherent structures similar to classical vortex tubes, arising intrinsically from superfluid dynamics without external influences.

Contribution

The study shows that quantized vortices in superfluids can form intrinsic coherent structures, confirmed through advanced simulations using a tree algorithm.

Findings

Bundles of quantized vortices appear as coherent structures.

These structures arise solely from Biot-Savart dynamics.

Similarity to classical vortex tubes is observed.

Abstract

This report addresses an important question discussed by the quantum turbulence community during the last decade: do quantized vortices form, in zero-temperature superfluids, coherent structures similar to vortex tubes in ordinary, viscous turbulence? So far the evidence provided by numerical simulations is that bundles of quantized vortices appear in finite-temperature superfluids, but from the interaction with existing coherent structures in the turbulent (viscous) normal fluid, rather than due to the intrinsic superfuid dynamics. In this report we show that, in very intense quantum turbulence (whose simulation was made possible by a tree algorithm), the vortex tangle contains small coherent vortical structures (bundles of quantized vortices) which arise from the Biot-Savart dynamics alone, and which are similar to the coherent structures observed in classical viscous turbulence.