Coherent excitonic resonances of natural quantum dots studied with optical 2D Fourier transform spectroscopy

ORAL

Abstract

Optical 2D Fourier transform spectroscopy [1] is used to study the coherent nonlinear response from interfacial (or ``natural'') GaAs quantum dots [2], found within the monolayer fluctuations of a quantum well. The low temperature ($\sim $6K) spectra show excitonic resonances from both the quantum dots and the quantum well, the former having a larger inhomogeneous distribution and narrower homogeneous linewidth. Variation of the population time delay (of the excitation sequence) and lattice temperature reveals a coupling associated with the phonon mediated, incoherent relaxation from the quantum well states to the lower energy quantum dots. [1] S. T. Cundiff, T. Zhang, A. D. Bristow, D. Karaiskaj, X. Dai, Acc. Chem. Res. \textbf{42}, 1423 (2009). [2] D. Gammon, E.S. Snow, B.V. Shanabrook, D.S. Katzer, and D. Park, PRL \textbf{76}, 3005 (1996).

*This work was supported by the U.S. Department of Energy and the National Science Foundation.

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Authors

  • Galan Moody

    • JILA, National Institute of Standards and Technology, and University of Colorado

  • Alan Bristow

    • JILA, National Institute of Standards and Technology, and University of Colorado

  • Mark Siemens

    • JILA, University of Colorado at Boulder
    • JILA, National Institute of Standards and Technology, and University of Colorado
    • Deparment of Physics and JILA, University of Colorado at Boulder

  • Xingcan Dai

    • JILA, National Institute of Standards and Technology, and University of Colorado

  • Denis Karaiskaj

    • JILA, National Institute of Standards and Technology, University of Colorado, and University of South Florida

  • Steven Cundiff

    • JILA, University of Colorado
    • JILA, National Institute of Standards and Technology, and University of Colorado, Boulder
    • JILA, National Institute of Standards and Technology, and University of Colorado
    • JILA, University of Colorado and NIST