title: Bayesian feedback control of a two-atom spin-state in an atom-cavity system.
abstract: We experimentally demonstrate real-time feedback control of the joint spin-state of two neutral cesium atoms inside a high finesse optical cavity. The quantum states are discriminated by their different cavity transmission levels. A Bayesian update formalism is used to estimate state occupation probabilities as well as transition rates. We stabilize the balanced two-atom mixed state, which is deterministically inaccessible, via feedback control and find very good agreement with Monte Carlo simulations. On average, the feedback loop achieves near optimal conditions by steering the system to the target state marginally exceeding the time to retrieve information about its state.
authors.affiliation: Institut für Angewandte Physik der Universität Bonn, Wegelerstrasse 8, 53115 Bonn, Germany. brakhane@iap.uni-bonn.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Brakhane
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Alt
authors.forename: Tobias
authors.initials: T
authors.lastname: Kampschulte
authors.forename: Miguel
authors.initials: M
authors.lastname: Martinez-Dorantes
authors.forename: René
authors.initials: R
authors.lastname: Reimann
authors.forename: Seokchan
authors.initials: S
authors.lastname: Yoon
authors.forename: Artur
authors.initials: A
authors.lastname: Widera
authors.forename: Dieter
authors.initials: D
authors.lastname: Meschede