title: Polarized single photon emission and photon bunching from an InGaN quantum dot on a GaN micropyramid.
abstract: We report on excitonic single photon emission and biexcitonic photon bunching from an InGaN quantum dot formed on the apex of a hexagonal GaN micropyramid. An approach to suppress uncorrelated emission from the pyramid base is proposed, a metal film is demonstrated to effectively screen background emission and thereby significantly enhance the signal-to-background ratio of the quantum dot emission. As a result, the second order coherence function at zero time delay g(2)(0) is significantly reduced (to g(2)(0) = 0.24, raw value) for the excitonic autocorrelation at a temperature of 12 K under continuous wave excitation, and a dominating single photon emission is demonstrated to survive up to 50 K. The deterioration of the g(2)(0)-value at elevated temperatures is well understood as the combined effect of reduced signal-to-background ratio and limited time resolution of the setup. This result underlines the great potential of site-controlled pyramidal dots as sources of fast polarized single photons.
authors.affiliation: Department of Physics, Chemistry, and Biology (IFM), Semiconductor Materials, Linköping University, SE-58183 Linköping, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Jemsson
authors.forename: Houssaine
authors.initials: H
authors.lastname: Machhadani
authors.forename: Per-Olof
authors.initials: PO
authors.lastname: Holtz
authors.forename: K Fredrik
authors.initials: KF
authors.lastname: Karlsson