Dynamic instabilities of giant vortices in dilute Bose-Einstein condensates

Pekko Kuopanportti, Mikko Möttönen

Alexander L. Fetter

Masahiro O. Takahashi, Takeshi Mizushima, K. Machida

Suvi Mirjami Virtanen, Mikko Möttönen, M.M. Salomaa

Pekko Kuopanportti, Emil Lundh, Jukka A. M. Huhtamäki +2 more

Motivated by a recent demonstration of cyclic addition of quantized vorticity into a Bose-Einstein condensate, the vortex pump, we study dynamical instabilities and core sizes of giant vortices. The core size is found to increase roughly as a square-root function of the quantum number of the vortex, whereas the strength of the dynamical instability either saturates to a fairly low value or increases extremely slowly for large quantum numbers. Our studies suggest that giant vortices of very high angular momenta may be achieved by gradually increasing the operation frequency of the vortex pump.

Jukka Räbinä, Pekko Kuopanportti, Markus Kivioja +2 more

We study the splitting dynamics of giant vortices in dilute Bose-Einstein condensates by numerically integrating the three-dimensional Gross-Pitaevskii equation in time. By taking advantage of tetrahedral tiling in the spatial discretization, we decrease the error and increase the reliability of the numerical method. An extensive survey of vortex splitting patterns is presented for different aspect ratios of the harmonic trapping potential. The discrete rotational symmetries of the splitting patterns that emerge in the time evolution are in good agreement with predictions obtained by solving the prevailing dynamical instabilities from the Bogoliubov equations. Furthermore, we observe intertwining of the split vortices in prolate condensates and a split-and-revival phenomenon in a spherical condensate.