Nondestructive Imaging of Spinor-Condensate Dynamics

The ability to probe the spatial dependence of the coherences and populations of a Spin-1 Bose condensate nondestructively opens a new window on the physics of this complex quantum fluid. In particular, we report recent measurements of the spin- dependent mean-field energy of a $^{87}$Rb condensate, responsible for its ferromagnetic character. The rich dynamics produced by the interplay between the spin-dependent interaction and the quadratic Zeeman shift are experimentally elucidated.