Formation of bright matter-wave solitons during the collapse of   Bose-Einstein condensates
  We observe bright matter-wave solitons form during the collapse of 85Rb condensates in a three-dimensional magnetic trap. The collapse is induced by using a Feshbach resonance to suddenly switch the atomic interactions from repulsive to attractive. Remnant condensates containing several times the critical number of atoms for the onset of instability are observed to survive the collapse. Under these conditions a highly robust configuration of solitons forms such that each soliton satisfies the condition for stability and neighboring solitons exhibit repulsive interactions. 
Simon L. Cornish, Sarah T. Thompson and Carl E. Wieman