title: Coherent control of an atomic collision in a cavity.
abstract: Following a recent proposal by S. B. Zheng and G. C. Guo [Phys. Rev. Lett. 85, 2392 (2000)], we report an experiment in which two Rydberg atoms crossing a nonresonant cavity are entangled by coherent energy exchange. The process, mediated by the virtual emission and absorption of a microwave photon, is characterized by a collision mixing angle 4 orders of magnitude larger than for atoms colliding in free space with the same impact parameter. The final entangled state is controlled by adjusting the atom-cavity detuning. This procedure, essentially insensitive to thermal fields and to photon decay, opens promising perspectives for complex entanglement manipulations.
authors.affiliation: Laboratoire Kastler Brossel, Département de Physique de l'Ecole Normale Supérieure, 24 rue Lhomond, F-75231, Paris Cedex 05, France.
authors.forename: S
authors.initials: S
authors.lastname: Osnaghi
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: 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