title: Efficient retrieval of a single excitation stored in an atomic ensemble.
abstract: We report significant improvements in the retrieval efficiency of a single excitation stored in an atomic ensemble and in the subsequent generation of strongly correlated pairs of photons. A 50% probability of transforming the stored excitation into one photon in a well-defined spatio-temporal mode at the output of the ensemble is demonstrated. These improvements are illustrated by the generation of high-quality heralded single photons with a suppression of the two-photon component below 1% of the value for a coherent state. A broad characterization of our system is performed for different parameters in order to provide input for the future design of realistic quantum networks.
authors.forename: Julien
authors.initials: J
authors.lastname: Laurat
authors.forename: Hugues
authors.initials: H
authors.lastname: de Riedmatten
authors.forename: Daniel
authors.initials: D
authors.lastname: Felinto
authors.forename: Chin-Wen
authors.initials: CW
authors.lastname: Chou
authors.forename: Erik W
authors.initials: EW
authors.lastname: Schomburg
authors.forename: H Jeff
authors.initials: HJ
authors.lastname: Kimble