title: A high-brightness source of narrowband, identical-photon pairs.
abstract: We generated narrowband pairs of nearly identical photons at a rate of 5 x 10(4) pairs per second from a laser-cooled atomic ensemble inside an optical cavity. A two-photon interference experiment demonstrated that the photons could be made 90% indistinguishable, a key requirement for quantum information-processing protocols. Used as a conditional single-photon source, the system operated near the fundamental limits on recovery efficiency (57%), Fourier transform-limited bandwidth, and pair-generation-rate-limited suppression of two-photon events (factor of 33 below the Poisson limit). Each photon had a spectral width of 1.1 megahertz, ideal for interacting with atomic ensembles that form the basis of proposed quantum memories and logic.
authors.affiliation: Department of Physics, MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. jkthomps@mit.edu
authors.forename: James K
authors.initials: JK
authors.lastname: Thompson
authors.forename: Jonathan
authors.initials: J
authors.lastname: Simon
authors.forename: Huanqian
authors.initials: H
authors.lastname: Loh
authors.forename: Vladan
authors.initials: V
authors.lastname: Vuletic