title: Observation of ground-state quantum beats in atomic spontaneous emission.
abstract: We report ground-state quantum beats in spontaneous emission from a continuously driven atomic ensemble. Beats are visible only in an intensity autocorrelation and evidence spontaneously generated coherence in radiative decay. Our measurement realizes a quantum eraser where a first photon detection prepares a superposition and a second erases the "which path" information in the intermediate state.
authors.affiliation: Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742-4111, USA.
authors.forename: D G
authors.initials: DG
authors.lastname: Norris
authors.forename: L A
authors.initials: LA
authors.lastname: Orozco
authors.forename: P
authors.initials: P
authors.lastname: Barberis-Blostein
authors.forename: H J
authors.initials: HJ
authors.lastname: Carmichael