De Luo

Collisions of matter-wave solitons

Atomic matter waves provide a controllable platform for studying the behaviour of solitons. In a lithium condensate, a characterization of the dynamics of collisions between solitons reveals a dependence on their relative phases.

Formation of matter-wave soliton trains by modulational instability

Solitons are localized wave packets whose dispersion is compensated by a nonlinearity. Solitons are observed in many wave settings including optics, fluids, plasmas, and matter-waves. Bright matter-wave solitons were first created by quenching the interactions in a quasi-one dimensional atomic Bose-Einstein condensate (BEC) from repulsive to attractive [1, 2]. Under some conditions a train of up to 10 solitons was formed [2]. Neighboring solitons were observed to repel one another, an effect that was attributed to an alternating π-0-π phase distribution. There has been a theoretical debate whether this phase structure is inherent to the formation of the train, or if it evolves through a series of mergers and annihilations between neighboring solitons that are in-phase, and hence attractive.