Confinement and precession of vortex pairs in coherently coupled Bose-Einstein condensates

TL;DR

This paper studies how vortex pairs in coherently coupled Bose-Einstein condensates behave under confinement and precession, revealing effects of Rabi coupling and domain wall dynamics through numerical and analytical methods.

Contribution

It introduces a detailed analysis of vortex pair dynamics in coupled BECs, highlighting the impact of Rabi coupling on vortex confinement and domain wall behavior, with analogies to quantum chromodynamics.

Findings

Rabi coupling influences vortex pair disintegration

Domain wall size affects vortex confinement

Numerical results align with analytical models

Abstract

The dynamic behavior of vortex pairs in two-component coherently (Rabi) coupled Bose-Einstein condensates is investigated in the presence of harmonic trapping. We discuss the role of the surface tension associated with the domain wall connecting two vortices in condensates of atoms occupying different spin states and its effect on the precession of the vortex pair. The results, based on the numerical solution of the Gross-Pitaevskii equations, are compared with the predictions of an analytical macroscopic model and are discussed as a function of the size of the pair, the Rabi coupling and the inter-component interaction. We show that the increase of the Rabi coupling results in the disintegration of the domain wall into smaller pieces, connecting vortices of new-created vortex pairs. The resulting scenario is the analogue of quark confinement and string breaking in quantum chromodynamics.