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HL: Fachverband Halbleiterphysik
HL 64: Poster II
HL 64.22: Poster
Donnerstag, 19. März 2020, 10:00–13:00, P1A
Time-resolved high-frequency Lock-In transport measurements on self-assembled quantum dots — •Felix Schaumburg1, Jens Kerski1, Jakob Penner1, Arne Ludwig2, Andreas D. Wieck2, Martin Geller1, and Axel Lorke1 — 1Faculty of Physics and CENIDE, University Duisburg-Essen, Germany — 2Chair of Applied Solid State Physics, Ruhr-University Bochum, Germany
Time-resolved transconductance measurements on self-assembled quantum dots (QDs) can be used to access excited spin- and charge states in an all-electrical measurement [1], an important step towards quantum state manipulation and detection for future quantum information technologies. For fast and high-fidelity measurements, the signal-to-noise ratio (SNR) of the read-out signal is of great importance. We present transconductance measurements with an significantly increased SNR up to single-shot measurements. For this, we combined transconductance with a Lock-In measurement scheme using the resonance frequency of an LC circuit. We use a high-mobility electron transistor (HEMT) with a layer of QDs, which are coupled to a two-dimensional electron gas (2DEG). This allows us to observe the tunnelling dynamics between the 2DEG and the QDs. A sinusoidal MHz-ac-voltage in resonance with the LC circuit is applied to the 2DEG in the Lock-In measurement. The transmitted signal is analysed with a Lock-In-Amplifier, exhibiting the regular transients of transconductance with an enhanced SNR.
[1] K. Eltrudis et al., Appl. Phys. Lett. 111, 092103 (2017).