2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/21970Josephson weak links in superconductors can be engineered such that the phase difference across the junction is $π$ ($π$-junction),leading to the reversal of the current. The conditions under which the analogous effect of supercurrent counterflow can be achieved in a double-well atomic Bose-Einstein condensate are investigated. It is shown that this effect is observable for condensates up to a few thousand atoms, which are initially prepared in an anti-symmetric '$π$-state' and subsequently subjected to a uniformly increasing magnetic field gradient. This effect is found to be only weakly-dependent on trap geometry, and can be observed in both attractive and repulsive condensates.A substantially revised manuscript (some figures removed, improved discussion and some additional material) is available on cond-mat/0312396Condensed Mattertext