Regensburg 2022 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 25: Poster 1

HL 25.58: Poster

Wednesday, September 7, 2022, 18:00–20:00, P2

Energy dependent tunnel coupling of QDs to a reservoir at elevated temperatures — •Ismail Bölükbasi¹, Ibrahim Engin¹, Patrick Lindner², Arn Baudzus¹, Andreas D. Wieck¹, Björn Sothmann³, and Arne Ludwig¹ — ¹Ruhr-Universität Bochum, D-44780 Bochum, Germany — ²TU Dortmund, D-44221, Dortmund, Germany — ³Theoretische Physik, Universität Duisburg-Essen and CENIDE, D-47048 Duisburg, Germany

Quantum dots have interesting physical properties and allow research in zero dimensional systems. They are used in modern displays and are highly efficient sources of high-fidelity single photons [1]. For their applicability, it is advantageous to understand the electrical properties and tunnelling behaviours of QDs coupled to a charge reservoir. Capacitance-voltage spectroscopy is used to characterize quantum dots by electronically accessing the quantized states. A resonance shift with temperature in the ground-state charging peaks, the s-type states [2] originates from the degeneracy of the one- and two electron quantum states. An approach to model these measurements with a master equation [3] can describe these shifts including excitonic and non-equilibrium states. It is however limited to constant tunnel-coupling. We present experimental observations like frequency dependent peak shifts that need an extended model and propose an improved master equation approach to address this behaviour.

[1] Tomm et al. (2021) Nat. Nanotechnol. 16(4) [2] Brinks et al. (2016) New Journal of Physics, 18(12). [3] Valentin et al. (2018) Physical Review B, 97(4).