title: Dynamics and Interaction of Vortex Lines in an Elongated Bose-Einstein Condensate.
abstract: We study the real-time dynamics of vortices in a large elongated Bose-Einstein condensate (BEC) of sodium atoms using a stroboscopic technique. Vortices are produced via the Kibble-Zurek mechanism in a quench across the BEC transition and they slowly precess keeping their orientation perpendicular to the long axis of the trap as expected for solitonic vortices in a highly anisotropic condensate. Good agreement with theoretical predictions is found for the precession period as a function of the orbit amplitude and the number of condensed atoms. In configurations with two or more vortices, we see signatures of vortex-vortex interaction in the shape and visibility of the orbits. In addition, when more than two vortices are present, their decay is faster than the thermal decay observed for one or two vortices. The possible role of vortex reconnection processes is discussed.
authors.affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Serafini
authors.affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Barbiero
authors.affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Debortoli
authors.affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy.|Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Donadello
authors.affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Larcher
authors.affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy.|Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Dalfovo
authors.affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy.|Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Lamporesi
authors.affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy.|Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Ferrari