Intermittent implosion and pattern formation of trapped Bose-Einstein condensates with an attractive interaction.

The collapsing dynamics of a trapped Bose-Einstein condensate with attractive interaction are revealed to exhibit two previously unknown phenomena. During the collapse, the condensate undergoes a series of rapid implosions that occur intermittently within a very small region. When the sign of the interaction is suddenly switched from repulsive to attractive, e.g., by the Feshbach resonance, density fluctuations grow to form various patterns such as a shell structure.