title: Single-Photon Superradiance from a Quantum Dot.
abstract: We report on the observation of single-photon superradiance from an exciton in a semiconductor quantum dot. The confinement by the quantum dot is strong enough for it to mimic a two-level atom, yet sufficiently weak to ensure superradiance. The electrostatic interaction between the electron and the hole comprising the exciton gives rise to an anharmonic spectrum, which we exploit to prepare the superradiant quantum state deterministically with a laser pulse. We observe a fivefold enhancement of the oscillator strength compared to conventional quantum dots. The enhancement is limited by the base temperature of our cryostat and may lead to oscillator strengths above 1000 from a single quantum emitter at optical frequencies.
authors.affiliation: Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
authors.forename: Petru
authors.initials: P
authors.lastname: Tighineanu
authors.affiliation: Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
authors.forename: Raphaël S
authors.initials: RS
authors.lastname: Daveau
authors.affiliation: Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
authors.forename: Tau B
authors.initials: TB
authors.lastname: Lehmann
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, CB3 0HE Cambridge, United Kingdom.
authors.forename: Harvey E
authors.initials: HE
authors.lastname: Beere
authors.affiliation: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, CB3 0HE Cambridge, United Kingdom.
authors.forename: David A
authors.initials: DA
authors.lastname: Ritchie
authors.affiliation: Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Lodahl
authors.affiliation: Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Stobbe