title: Spin self-rephasing and very long coherence times in a trapped atomic ensemble.
abstract: We perform Ramsey spectroscopy on the ground state of ultracold 87Rb atoms magnetically trapped on a chip in the Knudsen regime. Field inhomogeneities over the sample should limit the 1/e contrast decay time to about 3 s, while decay times of 58 ± 12 s are actually observed. We explain this surprising result by a spin self-rephasing mechanism induced by the identical spin rotation effect originating from particle indistinguishability. We propose a theory of this synchronization mechanism and obtain good agreement with the experimental observations. The effect is general and may appear in other physical systems.
authors.affiliation: Laboratoire Kastler Brossel, ENS, UPMC, CNRS, 24 rue Lhomond, 75005 Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Deutsch
authors.forename: F
authors.initials: F
authors.lastname: Ramirez-Martinez
authors.forename: C
authors.initials: C
authors.lastname: Lacroûte
authors.forename: F
authors.initials: F
authors.lastname: Reinhard
authors.forename: T
authors.initials: T
authors.lastname: Schneider
authors.forename: J N
authors.initials: JN
authors.lastname: Fuchs
authors.forename: F
authors.initials: F
authors.lastname: Piéchon
authors.forename: F
authors.initials: F
authors.lastname: Laloë
authors.forename: J
authors.initials: J
authors.lastname: Reichel
authors.forename: P
authors.initials: P
authors.lastname: Rosenbusch