Surface excitations, shape deformation and the long-time behavior in a stirred Bose-Einstein condensate

TL;DR

This paper investigates how surface excitations and shape deformations in a stirred Bose-Einstein condensate lead to vortex formation, trapping, and long-term behavior, revealing mechanisms for vortex manipulation.

Contribution

It provides new insights into vortex dynamics and shape deformation in BECs under rotation, highlighting the role of surface waves and obstacle potential.

Findings

Vortex dipoles can be trapped at the stirrer center even at slow stirring speeds.

Shape deformation becomes significant above a critical rotation velocity.

Long-term behavior includes trapped vortices and vortex manipulation possibilities.

Abstract

The surface excitations, shape deformation and the formation of persistent current for a Gaussian obstacle potential rotating in an highly oblate Bose-Einstein condensate(BEC)are investigated. Vortex dipole can be produced and trapped in the center of the stirrer even for slow motion of the stirring beam. When the barrier angular velocity is above some critical value, the condensate shape can be deformed remarkably according to the rotation frequency due to the existence of plenty of surface wave excitations. After a long enough time, a few vortices are found to be left either trapped in the condensate or pinned by the obstacle, a vortex dipole or several vortices can be trapped at the beam center, which enables the possibility of vortex manipulation.