Vortex formation in a slowly rotating Bose-Einstein condensate confined in a harmonic-plus-gaussian laser trap

TL;DR

This paper investigates vortex formation in rotating Bose-Einstein condensates within various laser-induced trapping potentials, revealing symmetry breaking and vortex creation even in non-interacting systems, based on experimental and theoretical analysis.

Contribution

It demonstrates how adjusting laser trap parameters induces vortex formation and symmetry breaking in both interacting and non-interacting Bose-Einstein condensates.

Findings

Vortices form in slowly rotating condensates with increased laser trap amplitude.

Symmetry breaking occurs when rotational frequency exceeds half the surface mode frequency.

Vortices can be created in non-interacting condensates within the same potential.

Abstract

Motivated by the recent experiment at ENS [ V. Bretin, S. Stock, Y. Seurin and, J. Dalibard, Phys. Rev. Lett. {\bf 92}, 050403 (2004)], we study a rotating (non-)interacting atomic Bose-Einstein condensate confined in a harmonic-plus-gaussian laser trap potential. By adjusting the amplitude of the laser potential, one can make quadratic-plus-quartic potential,purely quartic potential, and quartic-minus-quadratic potential. We show that an interacting Bose-Einstein condensate confined in a harmonic-plus-gaussian laser trap breaks the rotational symmetry of the Hamiltonian when rotational frequency is greater than one-half of the lowest energy surface mode frequency. We also show that by increasing the amplitude of the gaussian laser trap, a vortex appears in a slowly rotating Bose-Einstein condensate. Moreover, one can also create a vortex in non-interacting Bose-Einstein condensate confined in harmonic-plus-gaussian laser potential.