Observation of spin correlated matter-wave emission from spinor BEC

In this presentation, we introduce experimental observation of spin jet emission from F=1 spinor BEC in a quasi-2D trap. Starting from a BEC in (m=0) state of F=1 manifold, we quench the system to favor the equal composition of (+1), (-1) states. After binary collisions, the atomic spin states can be changed to m=1 and m=-1 states, where the excess internal Zeeman energy is released to the kinetic energy of the spin pair. This process can be stimulated further, forming matter-wave jets with the spin opposite spin states. The large spin-mixing rate of Lithium-7 is essential for the collisional amplification process. We study the dynamic features and the angular correlations for various spin states and reveal the spin-momentum correlation. Rotating the spin axis, the correlation peaks display a high contrast oscillation, indicating collective coherence of the atomic ensembles. We employ time-dependent BdG theory to provide a quantitative understanding of the experiment. Finally, we discuss the current experimental limitations and future improvements.