Confinement and precession of vortex pairs in coherently coupled Bose-Einstein condensates
Year: 2016
Authors: Tylutki M., Pitaevskii L. P., Recati A., Stringari S.
Autors Affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, Via Sommarive 14, I-38123 Povo, Italy
Kapitza Institute for Physical Problems, RAS, Kosygina 2, 119334 Moscow, Russia
Physik Department, Technische Universität München, James-Franck-Straße 1, D-85748 Garching, Germany
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 intercomponent interaction. We show that the increase of the Rabi coupling results in the disintegration of the domain wall into smaller pieces, connecting vortices of newly created vortex pairs. The resulting scenario is the analog of quark confinement and string breaking in quantum chromodynamics
Journal/Review: PHYSICAL REVIEW A
Volume: 93 Pages from: 043623 to: 043628
KeyWords: Coherently coupled Bose Gases; Vortices; String Breaking