Visualizing Pure Quantum Turbulence in Superfluid $^{3}$He: Andreev Reflection and its Spectral Properties

TL;DR

This paper demonstrates how Andreev reflection can be used to visualize and analyze quantum turbulence in superfluid helium-3, combining simulations and experiments to explore vortex dynamics at microscopic scales.

Contribution

It provides the first realistic 3D simulations of Andreev reflectance in superfluid helium-3 and compares these with experimental data, advancing understanding of quantum turbulence visualization.

Findings

Validated the relation between vortex-line density and Andreev reflectance.

First simulations of Andreev reflectance in a realistic 3D vortex tangle.

Experimental measurements probe turbulence at scales smaller than inter-vortex separation.

Abstract

Superfluid $^3$He-B in the zero-temperature limit offers a unique means of studying quantum turbulence by the Andreev reflection of quasiparticle excitations by the vortex flow fields. We validate the experimental visualization of turbulence in $^3$He-B by showing the relation between the vortex-line density and the Andreev reflectance of the vortex tangle in the first simulations of the Andreev reflectance by a realistic 3D vortex tangle, and comparing the results with the first experimental measurements able to probe quantum turbulence on length scales smaller than the inter-vortex separation.