Sw itching and self-trapping dynam ics of Bose± Einstein solitons

We investigate the dynamics of two weakly coupled Bose con- densates in long cigar-shaped traps. The Bose condensates are characterized by attractive mean-® eld interaction and consequently can be studied in terms of bright solitons. We exploit the analogy with directional ® bre couplers in nonlinear ® bre optics to uncover interesting dynamical regimes like switching of condensates from one trap to another and self-trapping of condensates. We also discuss the analogy between two weakly coupled Bose condensates and the Josephson junction in superuids and superconductors.