Dresden 2026 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 55: Quantum Dots and Wires: (Single) Photonics
HL 55.8: Vortrag
Freitag, 13. März 2026, 11:30–11:45, POT/0251
Spectral shadows of a single GaAs quantum dot — •Jens Hübner1, Kai Hühn1, Lena Klar1, Fei Ding1, Arne Ludwig2, Andreas D. Wieck2, and Michael Oestreich1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstraße 2, 30167 Hannover, Germany — 2Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum, Germany
Semiconductor quantum dots are today’s leading candidates for generating single and entangled photons. However, even the most advanced devices face performance limitations due to charge state fluctuations within the quantum dot and its surrounding environment. We have carried out detailed time-resolved resonance fluorescence measurements on an individual charge-tunable GaAs quantum dot, providing new insight into the spectral signatures generated by the complex landscape of unintentional impurities. For the neutral exciton and the negatively charged trion transitions, we uncover multiple Stark-shifted resonances, linked to rare spectral jumps smaller than the homogeneous linewidth. In other experiments, these jumps are typically obscured by measurement noise. In contrast, the positively charged and doubly negatively charged trions exhibit distinctly different behaviors. We quantify the underlying impurity charge dynamics over timescales ranging from sub-milliseconds to several seconds, and demonstrate that the hole population of the positively charged trion is limited in our state-of-the-art pin-structure by fast hole loss combined with slow hole recapture.
[Hühn et al., arXiv:507.20290 (2025)]
Keywords: quantum dots; resonance flourescence; charge fluctuations; single photon counting