Quantum turbulent velocity statistics and quasiclassical limit

TL;DR

This paper models quantum turbulence in superfluid helium to reconcile conflicting experimental results, showing that different length scales probed explain the transition from Gaussian to power-law velocity statistics.

Contribution

It provides a numerical model of quantum turbulence that clarifies the relationship between quantum and classical turbulence regimes based on vortex scale separation.

Findings

No contradiction between experiments when considering length scales

Average vortex distance marks quantum to classical transition

Transition from Gaussian to power-law statistics explained by scale differences

Abstract

Two research groups have measured turbulent velocity statistics in superfluid helium using different techniques. The results were in conflict: one experiment revealed Gaussian distributions(as observed in ordinary turbulence), the other experiment determined power-laws. To solve the apparent puzzle, we numerically model quantum turbulence as a tangle of vortex filaments, and conclude that there is no contradiction between the two experiments. The transition from Gaussian to power-law arises from the different length scales which are probed using the two techniques. We find that the average distance between the quantum vortices marks the separation between quantum and quasi-classical length scales.