2014/07/31 by G. Reithmaier, F. Flassig, Fabian Flassig +11
Chemistry · Computer Science · Physics and Astronomy · #Chemistry #Condensed matter physics #Exciton #Gallium arsenide #Materials science #Molecular physics #Optics #Optoelectronics #Phonon #Photon #Physics #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum dot #Relaxation (psychology) #Semiconductor Quantum Structures and Devices #Superconductivity #Wetting layer #cond-mat.mes-hall
paper · pdf · doi:10.1063/1.4894239
published as Appl. Phys. Lett. 105, 081107 (2014)
arxiv created 2014/08/15 · openalex publication_date 2014/08/25 · arxiv updated 2014/09/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 (τr) 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 τr ∝ P−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.