Spinor Dynamics in an Antiferromagnetic Spin-1 Condensate
A T. Black, Eduardo Gomez, Lincoln Turner, Sebastian Jung, Paul D. Lett
We observed coherent spin oscillations in an antiferromagnetic spin-1 Bose-Einstein condensate of sodium. The variation of the spin oscillations with magnetic field shows a clear signature of nonlinearity, in agreement with theoretical predictions that also predict anharmonic oscillations near a critical magnetic field. Measurements of the magnetic phase diagram agree with predictions made in the approximation of a single spatial mode. The oscillation period yields the best measurement to date of the sodium spin-dependent interaction coefficient, determining the difference between the sodium spin-dependent s-wavescattering lengths.