title: Observation of a topological and parity-dependent phase of m = 0 spin states.
abstract: A Ramsey interrogation scheme was used to measure the phase shift of laser-cooled 87Rb clock-transition pseudospins arising as a result of a reversal of a bias-magnetic field, i.e., B--> -B, during the interrogation. While no phase shift occurred when the reversal was sudden, the Ramsey fringes were shifted by a factor of pi when the reversal was adiabatic. We thus verified the prediction that the spin states |F,m=0 acquire a purely topological and parity-dependent phase factor of (-1)F as a result of B--> -B.
authors.affiliation: PRESTO, Japan Science and Technology Agency, Tokyo, Japan. usami.k.ab@m.titech.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Usami
authors.forename: Mikio
authors.initials: M
authors.lastname: Kozuma