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arXiv · 1710.08725

Vortices in self-bound dipolar droplets

André Cidrim·Francisco E. A. dos Santos·Emanuel A. L. Henn·Tommaso Macrì
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Abstract

Quantized vortices have been observed in a variety of superfluid systems, from $^4$He to condensates of alkali-metal bosons and ultracold Fermi gases along the BEC-BCS crossover. In this article we study the stability of singly quantized vortex lines in dilute dipolar self-bound droplets. We first discuss the energetic stability region of dipolar vortex excitations within a variational ansatz in the generalized nonlocal Gross-Pitaevskii functional that includes quantum fluctuation corrections. We find a wide region where stationary solutions corresponding to axially-symmetric vortex states exist. However, these singly-charged vortex states are shown to be unstable, either by splitting the droplet in two fragments or by vortex-line instabilities developed from Kelvin-wave excitations. These observations are the results of large-scale fully three-dimensional simulations in real time. We conclude with some experimental considerations for the observation of such states and suggest possible extensions of this work.

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André Cidrim, Francisco E. A. dos Santos, Emanuel A. L. Henn, Tommaso Macrì. 2018-08-18. Vortices in self-bound dipolar droplets. https://doi.org/10.1103/physreva.98.023618

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