Quantum turbulence in propagating superfluid vortex front

TL;DR

This study investigates the behavior of vortex fronts in superfluid 3He-B, revealing a transition from laminar to quantum turbulence and providing the first direct measurement of dissipation rates, which become temperature-independent at near-zero temperatures.

Contribution

It combines experimental, numerical, and theoretical approaches to characterize vortex front dynamics and dissipation in superfluid 3He-B, highlighting the role of Kelvin-wave cascades at low temperatures.

Findings

Vortex front nature changes from laminar to quantum turbulence with decreasing temperature.

First direct measurement of dissipation rate in turbulent vortex dynamics of 3He-B.

Dissipation becomes temperature-independent as T approaches 0, and is suppressed by Kelvin-wave cascades.

Abstract

We present experimental, numerical and theoretical studies of a vortex front propagating into a region of vortex-free flow of rotating superfluid 3He-B. We show that the nature of the front changes from laminar through quasi-classical turbulent to quantum turbulent with decreasing temperature. Our experiment provides the first direct measurement of the dissipation rate in turbulent vortex dynamics of 3He-B and demonstrates that the dissipation is temperature- and mutual friction-independent in the T->0 limit, and is strongly suppressed when the Kelvin-wave cascade on vortex lines is predicted to be involved in the turbulent energy transfer to smaller length scales.