In this poster, we will present recent experiments on a quenched ferromagnetic spinor BECs. In the first part, we present the observation of spin-momentum correlated matter-wave jets from spinor BECs [1]. Preparing a quasi-two-dimensional condensate in the mF=0 state, we quench the quadratic Zeeman energy to -2 kHz. Transversely propagating atomic beams in the mF=1 and mF=-1 state (mF =0 state) are generated due to superradiant collision process. Investigating angular correlation for each spin state, we reveal the strong correlation between spin and momentum, which suggests the possibility of being Einstein-Podolsky-Rosen (EPR) state. In the second part, we investigate the long-time relaxation dynamics after the quench [2,3]. Generated spin pairs form magnetic domains and are merged to display coarsening dynamics. We investigate correlation functions of the magnetization and observe the functions at different time collapse to a single function. Our result shows a good agreement with numerical simulation.
[1] K. Kim, J. Hur, S. Huh, S. Choi, and J.-Y. Choi, Phys. Rev. Lett. 127, 043401 (2021)
[2] L. A. Williamson and P. B. Blakie., Phys. Rev. Lett. 116, 025301 (2016)
[3] J. Hofmann, S. S. Natu, and S. Das Sarma, Phys. Rev. Lett. 113, 095702 (2014).