title: Nondestructive Rydberg atom counting with mesoscopic fields in a cavity.
abstract: We present an efficient, state-selective, nondemolition atom-counting procedure based on the dispersive interaction of a sample of circular Rydberg atoms with a mesoscopic field contained in a high-quality superconducting cavity. The state-dependent atomic index of refraction, proportional to the atom number, shifts the classical field phase. A homodyne procedure translates the information from the phase to the intensity. The final field intensity is readout by a mesoscopic atomic sample. This method opens promising routes for quantum information processing and nonclassical state generation with Rydberg atoms.
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: Maioli
authors.forename: T
authors.initials: T
authors.lastname: Meunier
authors.forename: S
authors.initials: S
authors.lastname: Gleyzes
authors.forename: A
authors.initials: A
authors.lastname: Auffeves
authors.forename: G
authors.initials: G
authors.lastname: Nogues
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