Bright matter wave solitons in Bose–Einstein condensates
Abstract
We review recent experimental and theoretical work on the creation \nof bright matter wave solitons in Bose–Einstein condensates. In two recent experiments, \nsolitons are formed from Bose–Einstein condensates of 7Li by utilizing \na Feshbach resonance to switch from repulsive to attractive interactions. \nThe solitons are made to propagate in a one-dimensional potential formed by a \nfocused laser beam. For repulsive interactions, the wavepacket undergoes dispersivewavepacket \nspreading, while for attractive interactions, localized solitons are \nformed. In our experiment, a multi-soliton train containing up to ten solitons is \nobserved to propagate without spreading for a duration of 2 s. Adjacent solitons \nare found to interact repulsively, in agreement with a calculation based on the \nnonlinear Schr¨odinger equation assuming that the soliton train is formed with an \nalternating phase structure. The origin of this phase structure is not entirely clear.