Phase separation and vortex states in binary mixture of Bose-Einstein condensates in the trapping potentials with displaced centers

TL;DR

This paper theoretically investigates how displacing the trapping potentials in a binary Bose-Einstein condensate mixture affects phase separation, vortex states, and the displacement of condensate centers, aligning with experimental observations.

Contribution

It demonstrates the impact of trap displacement on vortex states and condensate displacement, revealing control mechanisms for vortex exchange between condensates.

Findings

Small trap shifts cause significant condensate displacement.

Critical vortex velocities depend on trap shift and particle ratio.

Vortex states can be exchanged by shifting trap centers.

Abstract

The system of two simultaneously trapped codensates consisting of $^{87}Rb$ atoms in two different hyperfine states is investigated theoretically in the case when the minima of the trapping potentials are displaced with respect to each other. It is shown that the small shift of the minima of the trapping potentials leads to the considerable displacement of the centers of mass of the condensates, in agreement with the experiment. It is also shown that the critical angular velocities of the vortex states of the system drastically depend on the shift and the relative number of particles in the condensates, and there is a possibility to exchange the vortex states between condensates by shifting the centers of the trapping potentials.