Transitions in coherent oscillations between two trapped Bose-Einstein condensates

Abstract

By solving numerically the tunneling quantum dynamics between two trapped Bose-Einstein condensates (BEC's), we find two distinct time scales. On the short time scale, we recover semiclassical predictions such as ``macroscopic quantum self-trapping'' and the ``amplitude transition,'' first studied in the polaron context, and the $``\ensuremath{\pi}$ states,'' previously discovered in the context of BEC's. On a much longer time scale, quantum dynamics shows that self-trapping is destroyed in contrast to semiclassical behavior. However, this time scale increases exponentially with the total number of condensate atoms, indicating that self-trapping and $``\ensuremath{\pi}$ states'' would be relevant and experimentally observable in the tunneling of BEC's.