Regensburg 2019 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 35: HL Poster II

HL 35.48: Poster

Wednesday, April 3, 2019, 17:30–20:00, Poster E

Single hole storage and non-equilibrium tunneling dynamics of quantum dots — •Carsten Ebler, Andreas D. Wieck, and Arne Ludwig — Ruhr-Universität Bochum, Bochum, Germany

Approaching the goal of a memory, storing single charge quanta, especially in quantum dots are interesting. Therefore, we use epitaxially grown self-assembled InAs QDs (SAQD) as crystalline hosts compatible with coupling to photons. This is envisaged as a progress compared to amorphous indirect semiconductors used in today’s flash memories [1]. We establish SAQDs in tunnel contact with a 2-dimensional electron gas (2DEG), manipulate the system with electronical and optical pulses and perform time resolved conductivity measurements of the 2DEG to readout the charge occupation of the QDs [2]. The structure is biased such, that the Fermi level is in electronic resonance with the X⁰ state in the QD to store one single hole. This metastable hole state is read out over conductivity changes of the 2DEG. Thereby it is possible to resolve electron tunneling dynamics and furthermore the interaction with the holes trapped inside the QDs. We prove metastable hole storage for at least 10 s and successful readout. Further experimentation with different voltage pulses provide information about tunneling processes of the electron states and dynamics of non-equilibrium states. [1] A. Marent et al, Semiconductor Science and Technology 26, 014026 (2011) [2] B. Marquardt1, et al, Appl. Phys. Lett. 95, 022113 (2009)