Coherent oscillations between two weakly coupled Bose-Einstein condensates:: Josephson effects, ? oscillations, and macroscopic quantum self-trapping
Year: 1999
Authors: Raghavan S., Smerzi A., Fantoni S., Shenoy S.R.
Autors Affiliation: Abdus Salaam Int Ctr Theoret Phys, I-34100 Trieste, Italy; Ist Nazl Fis Mat, I-34014 Trieste, Italy; Scuola Int Super Studi Avanzati, I-34014 Trieste, Italy.
Abstract: We discuss the coherent atomic oscillations between two weakly coupled Bose-Einstein condensates. The weak link is provided by a laser barrier in a (possibly asymmetric) double-well trap or by Raman coupling between two condensates in different hyperfine levels. The boson Josephson junction (BJJ) dynamics is described by the two-mode nonlinear Gross-Pitaevskii equation that is solved analytically in terms of elliptic functions. The BJJ, beings a neutral, isolated system, allows the investigations of dynamical regimes for the phase difference across the junction and for the population imbalance that are not accessible with superconductor Josephson junctions (SJJ’s). These include oscillations with either or both of the following properties: (i) the time-averaged value of the phase is equal to pi (pi-phase oscillations); (ii) the average population imbalance is nonzero, in states with macroscopic quantum self-trapping. The (nonsinusoidal) generalization of the SJJ ac and plasma oscillations and the Shapiro resonance can also be observed. We predict the collapse of experimental data (corresponding to different trap geometries and the total number of condensate atoms) onto a single universal curve for the inverse period of oscillations. Analogies with Josephson oscillations between two weakly coupled reservoirs of He-3-B and the internal Josephson effect in He-3-A are also discussed. [S1050-2947(98)05912-5].
Journal/Review: PHYSICAL REVIEW A
Volume: 59 (1) Pages from: 620 to: 633
KeyWords: Collective Excitations; Atoms; Gas; Equation; Systems; DimerDOI: 10.1103/PhysRevA.59.620Citations: 861data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-10-20References taken from IsiWeb of Knowledge: (subscribers only)