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MON: Monday Contributed Sessions
MON 22: Quantum Transport II
MON 22.5: Talk
Monday, September 8, 2025, 17:30–17:45, ZHG104
Decoding undesired charge dynamics in gated GaAs quantum dots — •Lena Klar1, Kai Hühn1, Arne Ludwig2, Andreas Wieck2, Jens Hübner1, and Michael Oestreich1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstraße 2, 30167 Hannover, Germany — 2Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum, Germany
Single semiconductor quantum dots (QDs) exhibit high potential as single-photon sources and are promising candidates for solid state qubits [1,2]. However, fluctuations in their charge state and in the surrounding semiconductor matrix significantly affect their optical absorption and emission spectra, even for gated quantum dots. Using two-colour resonance fluorescence spectroscopy, we investigate these fluctuations in a gated GaAs/(AlGa)As-QD in dependence on the QD charge state, temperature, and laser intensity. The experiment reveals not only standard telegraph noise but also subtle noise contributions from the QD’s environment, which deteriorate single photon QD sources. Calculations and numerical simulations based on light induced charge dynamics and an alternating occupation of charge traps surrounding the QD are in good agreement with the experimental results and show optimisation perspectives for GaAs QD single photon emitters.
[1] Y. Arakawa, M. J. Holmes, Appl. Phys. Rev. 7, 021309 (2020).
[2] A. Chatterjee et al., Nat. Rev. Phys. 3, 157-177 (2021).
Keywords: Quantum Dot; Charge Noise; Spectroscopy; Single Photon Source