  Experiments on ultra-cold attractive Bose-Einstein Condensates (BECs) have
demonstrated that at low dimensions atomic clouds can form localized objects,
propagating for long times without significant changes in their shapes and
attributed to bright matter-wave solitons, which are coherent objects. We
consider the dynamics of bright soliton trains from the perspective of
many-boson physics. The fate of matter-wave soliton trains is actually to
quickly loose their coherence and become macroscopically fragmented BECs. The
death of the coherent matter-wave soliton trains gives birth to fragmented
objects, whose quantum properties and experimental signatures differ
substantially from what is currently assumed.
