A carrier relaxation bottleneck probed in single InGaAs quantum dots using integrated superconducting single photon detectors

Journal Article · Mon Aug 25 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4894239· OSTI ID:22310934

Flassig, F.; Hasch, P.; Lichtmannecker, S.; Kaniber, M. ^[1]; Müller, K. ^[1]; Vučković, J. ^[2]; Gross, R. ^[3]

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1. Walter Schottky Institut, Technische Universität München (Germany)
2. E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305 (United States)
3. Walther Meißner Institut, Bayerische Akademie der Wissenschaften, Garching (Germany)

Using integrated superconducting single photon detectors, we probe ultra-slow exciton capture and relaxation dynamics in single self-assembled InGaAs quantum dots embedded in a GaAs ridge waveguide. Time-resolved luminescence measurements performed with on- and off-chip detection reveal a continuous decrease in the carrier relaxation time from 1.22 ± 0.07 ns to 0.10 ± 0.07 ns upon increasing the number of non-resonantly injected carriers. By comparing off-chip time-resolved spectroscopy with spectrally integrated on-chip measurements, we identify the observed dynamics in the rise time (τ{sub r}) as arising from a relaxation bottleneck at low excitation levels. From the comparison with the temporal dynamics of the single exciton transition with the on-chip emission signal, we conclude that the relaxation bottleneck is circumvented by the presence of charge carriers occupying states in the bulk material and the two-dimensional wetting layer continuum. A characteristic τ{sub r} ∝ P{sup −2∕3} power law dependence is observed suggesting Auger-type scattering between carriers trapped in the quantum dot and the two-dimensional wetting layer continuum which circumvents the phonon relaxation bottleneck.

• OSTI ID: 22310934
• Journal Information: Applied Physics Letters, Vol. 105, Issue 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CAPTURE
CARRIERS
CHARGE CARRIERS
DETECTION
EXCITATION
GALLIUM ARSENIDES
INDIUM COMPOUNDS
LAYERS
LUMINESCENCE
PHOTODETECTORS
PHOTONS
QUANTUM DOTS
RELAXATION TIME
SCATTERING
SPECTROSCOPY
SUPERCONDUCTING DEVICES
TIME RESOLUTION
TRAPPING
TWO-DIMENSIONAL CALCULATIONS