title: Direct observation of tunneling and nonlinear self-trapping in a single bosonic Josephson junction.
abstract: We report on the first realization of a single bosonic Josephson junction, implemented by two weakly linked Bose-Einstein condensates in a double-well potential. In order to fully investigate the nonlinear tunneling dynamics we measure the density distribution in situ and deduce the evolution of the relative phase between the two condensates from interference fringes. Our results verify the predicted nonlinear generalization of tunneling oscillations in superconducting and superfluid Josephson junctions. Additionally, we confirm a novel nonlinear effect known as macroscopic quantum self-trapping, which leads to the inhibition of large amplitude tunneling oscillations.
authors.affiliation: Kirchhoff-Institut für Physik, Universität Heidelberg, Im Neuenheimer Feld 227, D-69120 Heidelberg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Albiez
authors.forename: Rudolf
authors.initials: R
authors.lastname: Gati
authors.forename: Jonas
authors.initials: J
authors.lastname: Fölling
authors.forename: Stefan
authors.initials: S
authors.lastname: Hunsmann
authors.forename: Matteo
authors.initials: M
authors.lastname: Cristiani
authors.forename: Markus K
authors.initials: MK
authors.lastname: Oberthaler