Time-resolved luminescence of hierarchically self-assembled GaAs/AlGaAs quantum dots

ORAL

Abstract

Hierarchically self-assembled GaAs/AlGaAs quantum dots are promising building blocks for quantum information processing and novel lasers because they combine the tight confinement of InGaAs dots with the size homogeneity and a shorter emission wavelength of the GaAs/AlGaAs system at which many photodetectors are especially sensitive. So far, the emission dynamics of these structures has been unexplored. With a streak camera connected to a confocal microscope, we have measured the luminescence dynamics after direct optical picosecond excitation into the quantum dot states at a sample temperature of 10 K. Ensembles of high-density quantum dots (30 dots/$\mu $m$^{2})$ with well-separated transitions give information on state filling as well as intra- and interband relaxation. Single quantum dots on low-density samples (0.5 dots/$\mu $m$^{2})$ with microelectronvolt emission line widths reveal furthermore the time scale of biexciton formation and decay, as well as coherent effects.

*This work is supported by NSF DMR-0605854.

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Authors

  • Botao Zhang

    • Department of Physics and Astronomy, University of Pittsburgh, USA
    • University of Pittsburgh

  • Armando Rastelli

    • Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden, Germany
    • Leibniz-Institut f\"ur Festk\"orper- und Werkstoffforschung Dresden, Helmholtzstrasse 20, 01067-Dresden, Germany

  • Oliver Schmidt

    • Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden, Germany

  • Jeremy Levy

    • Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260
    • Department of Physics and Astronomy, University of Pittsburgh
    • University of Pittsburgh

  • David Snoke

    • Department of Physics and Astronomy, University of Pittsburgh
    • University of Pittsburgh
    • Dept. of Physics and Astronomy, University of Pittsburgh

  • Albert Heberle

    • Sullivan Park R\&D Center, Corning Incorporated and Department of Physics and Astronomy, University of Pittsburgh, USA
    • Sullivan Park R\&D Center, Corning Incorporated and University of Pittsburgh