title: Manipulation of nonclassical atomic spin states.
abstract: We report successful manipulation of nonclassical atomic spin states. We apply an off-resonant noncircularly-polarized light pulse to a measurement-induced squeezed spin state of a cold atomic ensemble. By changing the pulse duration, we clearly observe a rotation of the anisotropic quantum-noise distribution in good contrast with the case of manipulation of a coherent spin state where the quantum-noise distribution is always isotropic. This is an important step for quantum state tomography, quantum swapping, and precision spectroscopic measurement.
authors.affiliation: Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Takano
authors.forename: Shin-ichi-ro
authors.initials: SR
authors.lastname: Tanaka
authors.forename: Ryo
authors.initials: R
authors.lastname: Namiki
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Takahashi