Dynamical stability of multiply quntized vortices in Bose-Einstein condensates

Tapio Simula, Suvi Mirjami Virtanen, M.M. Salomaa

A. Cidrim, F. E. A. dos Santos, Vanderlei Salvador Bagnato

Mikko Möttönen, Takeshi Mizushima, Tomoya Isoshima +2 more

Jan Stockhofe, P. G. Kevrekidis, Peter Schmelcher

Luca Giacomelli, Iacopo Carusotto

This paper shows that multiply quantized vortices in two-dimensional Bose-Einstein condensates display instabilities analogous to the ergoregion instabilities of rotating relativistic spacetimes. This implies that multiply quantized vortices are dynamically unstable in an otherwise uniform condensate.

Luca Giacomelli, Iacopo Carusotto

We investigate the stability of vortices in two-dimensional Bose--Einstein condensates. In analogy with rotating spacetimes and with a careful account of boundary conditions, we show that the dynamical instability of multiply quantized vortices in trapped condensates persists in untrapped, spatially homogeneous geometries and has an ergoregion nature with some modification due to the peculiar dispersion of Bogoliubov sound. Our results open new perspectives to the physics of vortices in trapped condensates, where multiply quantized vortices can be stabilized by interference effects and singly charged vortices can become unstable in suitably designed trap potentials. We show how superradiant scattering can be observed also in the short-time dynamics of dynamically unstable systems, providing an alternative point of view on dynamical (in)stability phenomena in spatially finite systems.