title: Direct measurement of the Wigner function of a one-photon Fock state in a cavity.
abstract: We have measured the complete Wigner function W of the vacuum and of a single-photon state for a field stored in a high-Q cavity. This experiment implements the direct Lutterbach and Davidovich method [L. G. Lutterbach and L. Davidovich, Phys. Rev. Lett. 78, 2547 (1997)]] and is based on the dispersive interaction of a single circular Rydberg atom with the cavity field. The nonclassical nature of the single-photon field is exhibited by a region of negative W values. Extensions to other nonclassical cavity field states are discussed.
authors.affiliation: Laboratoire Kastler Brossel, Département de Physique de l'Ecole Normale Supérieure, 24 rue Lhomond, F-75231 Paris Cedex 05, France.
authors.forename: P
authors.initials: P
authors.lastname: Bertet
authors.forename: A
authors.initials: A
authors.lastname: Auffeves
authors.forename: P
authors.initials: P
authors.lastname: Maioli
authors.forename: S
authors.initials: S
authors.lastname: Osnaghi
authors.forename: T
authors.initials: T
authors.lastname: Meunier
authors.forename: M
authors.initials: M
authors.lastname: Brune
authors.forename: J M
authors.initials: JM
authors.lastname: Raimond
authors.forename: S
authors.initials: S
authors.lastname: Haroche