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arXiv · 1705.03236

The onset of nanoscale dissipation in superfluid He-4 at zero temperature: the role of vortex shedding and cavitation

Francesco Ancilotto·Manuel Barranco·Marti Pi·Jussi Eloranta
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Abstract

Two-dimensional flow past an infinitely long cylinder of nanoscopic radius in superfluid He-4 at zero temperature is studied by time-dependent density functional theory. The calculations reveal two distinct critical phenomena for the onset of dissipation: 1) vortex-antivortex pair shedding from the periphery of the moving cylinder and 2) appearance of cavitation in the wake, which possesses similar geometry as observed experimentally for fast moving micrometer-scale particles in superfluid He-4. Vortex pairs with the same circulation are occasionally emitted in the form of dimers, which constitute the building blocks for the Benard-von Karman vortex street structure observed in classical turbulent fluids and Bose-Einstein condensates. The cavitation induced dissipation mechanism should be common to all superfluids that are self-bound and have a finite surface tension, which include the recently discovered self-bound droplets in ultracold Bose gases.

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Francesco Ancilotto, Manuel Barranco, Marti Pi, Jussi Eloranta. 2017-05-09. The onset of nanoscale dissipation in superfluid He-4 at zero temperature: the role of vortex shedding and cavitation. https://doi.org/10.1103/physrevb.96.064503

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