A vortex filament tracking method for the Gross-Pitaevskii model of a superfluid

Alberto Villois, Giorgio Krstulovic, Davide Proment, Hayder Salman

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

We present an accurate and robust numerical method to track quantised vortex lines in a superfluid described by the Gross-Pitaevskii equation. By utilising the pseudo-vorticity field of the associated complex scalar order parameter of the superfluid, we are able to track the topological defects of the superfluid and reconstruct the vortex lines which correspond to zeros of the field. Throughout, we assume our field is periodic to allow us to make extensive use of the Fourier representation of the field and its derivatives in order to retain spectral accuracy. We present several case studies to test the precision of the method which include the evaluation of the curvature and torsion of a torus vortex knot, and the measurement of the Kelvin wave spectrum of a vortex line and a vortex ring. The method we present makes no a priori assumptions on the geometry of the vortices and is therefore applicable to a wide range of systems such as a superfluid in a turbulent state that is characterised by many vortex rings coexisting with sound waves. This allows us to track the positions of the vortex filaments in a dense turbulent vortex tangle and extract statistical information about the distribution of the size of the vortex rings and the inter-vortex separations. In principle, the method can be extended to track similar topological defects arising in other physical systems.

Original languageEnglish
Article number415502
JournalJournal of Physics A: Mathematical and Theoretical
Volume49
Issue number41
DOIs
Publication statusPublished - 23 Sep 2016

Keywords

  • Gross-Pitaevskii equation
  • quantised vortices
  • quantum turbulence
  • superfluid
  • topological defects
  • vortex dynamics

ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Modelling and Simulation
  • Mathematical Physics
  • Physics and Astronomy(all)

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