Berlin 2018 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 19: Quantum dots and wires: Transport properties

HL 19.2: Talk

Tuesday, March 13, 2018, 09:45–10:00, A 151

Illumination-induced non-equilibrium charge states in self-assembled quantum dots — Sascha R. Valentin¹, Jonathan Schwinger¹, Pia Eickelmann^1,2, Patrick A. Labud¹, Andreas D. Wieck¹, Björn Sothmann², and •Arne Ludwig¹ — ¹Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum, Germany — ²Fakultät für Physik und CENIDE, Universität Duisburg-Essen, Lotharstraße 1, 47048 Duisburg, Germany

We report on capacitance-voltage spectroscopy of self-assembled InAs quantum dots under constant illumination [1]. Besides the electronic and excitonic charging peaks in the spectrum reported earlier [2], we find additional resonances associated with non-equilibrium state tunneling unseen in C(V) measurements before. We derive a master-equation based model to assign the corresponding quantum state tunneling to the observed peaks. C(V) spectroscopy in a magnetic field is used to verify the model-assigned non-equilibrium peaks. The model is able to quantitatively address various experimental findings in C(V) spectroscopy of quantum dots such as the frequency and illumination dependent peak height, a thermal shift of the tunneling resonances [3] and the occurrence of the additional non-equilibrium peaks.

[1] S. R. Valentin, et al., arXiv:1710.07545.

[2] P. Labud, A. Ludwig, A. Wieck, G. Bester, and D. Reuter, Phys. Rev. Lett. 112, 046803 (2014).

[3] F. Brinks, A. D. Wieck, and A. Ludwig, New J. Phys. 18, 123019 (2016).