title: Spinor dynamics in an antiferromagnetic spin-1 condensate.
abstract: We observe 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 theory, which also predicts 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 that the difference between the sodium spin-dependent s-wave scattering lengths a(f=2) - a(f=0) is 2.47+/-0.27 Bohr radii.
authors.affiliation: Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: A T
authors.initials: AT
authors.lastname: Black
authors.forename: E
authors.initials: E
authors.lastname: Gomez
authors.forename: L D
authors.initials: LD
authors.lastname: Turner
authors.forename: S
authors.initials: S
authors.lastname: Jung
authors.forename: P D
authors.initials: PD
authors.lastname: Lett