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arXiv:1410.4679 · Physical Review B

Vortex arrays in a rotating superfluid He4 nanocylinder

Francesco Ancilotto, Martí Pi, M. Barranco

Published Nov 24, 2014• 18 citations
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Abstract

Within density functional theory, we investigate stationary many-vortex structures in a rotating $^{4}\mathrm{He}$ nanocylinder at zero temperature. We compute the stability diagram and compare our results with the classical model of vortical lines in an inviscid and incompressible fluid. Scaling the results to millimeter-size buckets, they can be compared with experiments on vortex arrays conducted in the past. Motivated by recent experiments that have used atomic impurities as a means of visualizing vortices in superfluid $^{4}\mathrm{He}$ droplets, we have also considered the formation of chains of xenon atoms along a vortex line and the interaction between xenon atoms inside the same vortex and on different neighboring vortex lines.

DOI
10.1103/physrevb.90.174512

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Superfluid helium nanodroplets are an ideal environment for the formation of metastable, self-organized dopant nanostructures. However, the presence of vortices often hinders their formation. Here, we demonstrate the generation of vortex-free helium nanodroplets and explore the size range in which they can be produced. From x-ray diffraction images of xenon-doped droplets, we identify that single compact structures, assigned to vortex-free aggregation, prevail up to 10^{8} atoms per droplet. This finding builds the basis for exploring the assembly of far-from-equilibrium nanostructures at low temperatures.
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