title: Cavity-modified collective Rayleigh scattering of two atoms.
abstract: We report on the observation of cooperative radiation of exactly two neutral atoms strongly coupled to the single mode field of an optical cavity, which is close to the lossless-cavity limit. Monitoring the cavity output power, we observe constructive and destructive interference of collective Rayleigh scattering for certain relative distances between the two atoms. Because of cavity backaction onto the atoms, the cavity output power for the constructive two-atom case (N=2) is almost equal to the single-emitter case (N=1), which is in contrast to free-space where one would expect an N^{2} scaling of the power. These effects are quantitatively explained by a classical model as well as by a quantum mechanical model based on Dicke states. We extract information on the relative phases of the light fields at the atom positions and employ advanced cooling to reduce the jump rate between the constructive and destructive atom configurations. Thereby we improve the control over the system to a level where the implementation of two-atom entanglement schemes involving optical cavities becomes realistic.
authors: Institut für Angewandte Physik, Universität Bonn, Wegelerstraße 8, 53115 Bonn, Germany.
authors: René
authors: R
authors: Reimann
authors: Institut für Angewandte Physik, Universität Bonn, Wegelerstraße 8, 53115 Bonn, Germany.
authors: Wolfgang
authors: W
authors: Alt
authors: Departement Physik, Universität Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
authors: Tobias
authors: T
authors: Kampschulte
authors: Institut für Angewandte Physik, Universität Bonn, Wegelerstraße 8, 53115 Bonn, Germany.
authors: Tobias
authors: T
authors: Macha
authors: Institut für Angewandte Physik, Universität Bonn, Wegelerstraße 8, 53115 Bonn, Germany.
authors: Lothar
authors: L
authors: Ratschbacher
authors: Institut für Angewandte Physik, Universität Bonn, Wegelerstraße 8, 53115 Bonn, Germany.
authors: Natalie
authors: N
authors: Thau
authors: Institut für Angewandte Physik, Universität Bonn, Wegelerstraße 8, 53115 Bonn, Germany.
authors: Seokchan
authors: S
authors: Yoon
authors: Institut für Angewandte Physik, Universität Bonn, Wegelerstraße 8, 53115 Bonn, Germany.
authors: Dieter
authors: D
authors: Meschede