title: Josephson effects in dilute bose-einstein condensates
abstract: We propose an experiment that would demonstrate the dc and ac Josephson effects in two weakly linked Bose-Einstein condensates. We consider a time-dependent barrier, moving adiabatically across the trapping potential. The phase dynamics are governed by a "driven-pendulum" equation, as in current-driven superconducting Josephson junctions. At a critical velocity of the barrier (proportional to the critical tunneling current), there is a sharp transition between the dc and ac regimes. The signature is a sudden jump of a large fraction of the relative condensate population. Analytical results are compared with a numerical integration of the Gross-Pitaevskii equation, in an experimentally realistic situation.
authors.affiliation: Istituto Nazionale di Fisica della Materia and International School for Advanced Studies, via Beirut 2/4, I-34014, Trieste, Italy.
authors.initials: S
authors.lastname: Giovanazzi
authors.initials: A
authors.lastname: Smerzi
authors.initials: S
authors.lastname: Fantoni