Volume 109, Number 4, February 2015
|Number of page(s)||6|
|Published online||27 February 2015|
Phase slips and vortex dynamics in Josephson oscillations between Bose-Einstein condensates
1 INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento - Via Sommarive 14, 38123 Povo, Italy
2 Departament d'Estructura i Constituents de la Matèria and IN2UB, Facultat de Física, Universitat de Barcelona Martí i Franquès 1, 08028 Barcelona, Spain
3 Technische Universität München - James-Franck-Straße 1, 85748 Garching, Germany
4 IFIBA-CONICET - Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires, Argentina
5 QSTAR, INO-CNR and LENS - Largo Enrico Fermi 2, 50125 Firenze, Italy
Received: 8 October 2014
Accepted: 3 February 2015
We study the relation between Josephson dynamics and topological excitations in a dilute Bose-Einstein condensate confined in a double-well trap. We show that the phase slips responsible for the self-trapping regime are created by vortex rings entering and annihilating inside the weak-link region or created at the center of the barrier and expanding outside the system. Large amplitude oscillations just before the onset of self-trapping are also strictly connected with the dynamics of vortex rings at the edges of the inter-well barrier. Our results extend and analyze the dynamics of the vortex-induced phase slippages suggested a few decades ago in relation to the “ac” Josephson effect of superconducting and superfluid helium systems.
PACS: 03.75.Lm – Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations / 03.75.Kk – Dynamic properties of condensates; collective and hydrodynamic excitations, superfluid flow
© EPLA, 2015
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