Driven Bose-Einstein condensates and Bose fireworks
Floquet engineering, periodic modulation of a system, has been employed in condensed matter and cold atom systems as a powerful tool to create new quantum phases and phenomena. In many cases, however, the periodic driving only controls the system on a single-particle level. Here we demonstrate periodic driving of inter-particle interactions within a Bose-Einstein condensate, which leads to dramatic dynamics of the condensate. Intriguingly we observe runaway stimulated collisions in condensates leading to collective emission of matter-wave jets that resemble fireworks. In addition to the primary emission of jets, we also see a high-harmonic generation of jets with complex correlations. Based on a versatile pattern recognition scheme, we identify a "turtle" pattern of correlations that reveals the underlying microscopic processes. In the future, we plan to combine such modulation of interaction with lattice shaking that controls single-particle dispersion to create density-dependent tunneling, the first step toward quantum simulation of dynamical gauge fields.