SKM 2023 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 29: Materials and devices for quantum technology I

HL 29.2: Talk

Wednesday, March 29, 2023, 15:15–15:30, POT 151

Accessing broad-band quantum dynamics in the low photon regime — •Markus Sifft¹, A. Kurzmann², J. Kerski², R. Schott¹, A. Ludwig¹, A. D. Wieck¹, A. Lorke², M. Geller², and D. Hägele¹ — ¹Ruhr University Bochum, Germany — ²Faculty of Physics and CENIDE, University of Duisburg-Essen, Germany

The analysis of quantum dynamics from measurement records z(t) poses a fundamental challenge in many fields of science and engineering. Measurement records are notoriously difficult to analyze due to inherent or additional background noise, loss of e.g., probe photons, and finite measurement times. We recently introduced quantum polyspectra as a tool to analyze z(t) in terms of higher order spectra whose shapes can be predicted within a quantum master equation approach [1,2]. Here, we solve the problem of analyzing the blinking (charging) dynamics of a semiconductor quantum dot in the regime of low photon rates or high photon loss [3]. The usual telegraph noise of binned photon click events changes to rare single clicks in case of high photon loss. Fitting theoretical quantum polyspectra to their measured counterparts gives full access to the in- and out-tunneling rates γ_in, γ_out of electrons despite low average photon rates γ_p ≪ γ_in + γ_out. We demonstrate the successful evaluation of tunneling rates at up to 99.9 % loss of photons surpassing a previous scheme that handled a 98 % loss using the same data. [1] Hägele et al., PRB 98, 205143 (2018), [2] Sifft et al., PRR 3, 033123 (2021), [3] Sifft et al., arXiv:2109.05862