Friction-enhanced lifetime of bundled quantum vortices

Abstract

Experiments in the early 1980s have shown that a compact bundle of quantum vortex rings in superfluid helium remains coherent and travels a significant distance compared to its size. This is surprising because a single vortex ring, under the effect of friction with the background of thermal excitations (the so-called normal fluid), would quickly lose energy and decay. The observation of these long-lived vortex structures has remained an unsettled question since their experimental detection. In this work, by taking into account the fully coupled dynamics of superfluid vortices and the normal fluid, we show that the motion of the superfluid bundle generates a large-scale wake in the normal fluid which reduces the overall friction experienced by the bundle, enhancing its lifetime. This collective effect is similar to the drag reduction observed in systems of active, hydrodynamically cooperative agents such as bacteria in aqueous suspensions, fungal spores in the atmosphere and cyclists in pelotons.

arXiv comment10 pages, 4 figures

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Cited by in corpus (6)

• Rotating Curved Spacetime Signatures from a Giant Quantum Vortex
• Higher-order statistics and intermittency of a two-fluid HVBK quantum turbulent flow
• Kelvin waves, mutual friction, and fluctuations in the Gross-Pitaevskii model
• Newtonian-like behavior of starting vortex flow in superfluid helium at high Reynolds numbers
• Quantum vortex driven Kelvin wave in the thermal background of superfluid helium
• Coupling Navier-Stokes and Gross-Pitaevskii equations for the numerical simulation of two-fluid quantum flows