On Noise-Sensitive Automatic Tuning of Gate-Defined Sensor Dots

Fabian Hader; Jan Vogelbruch; Simon Humpohl; Tobias Hangleiter; Chimezie Eguzo; Stefan Heinen; Stefanie Meyer; Stefan van Waasen

doi:10.1109/tqe.2023.3255743

arXiv · 2508.07898

On Noise-Sensitive Automatic Tuning of Gate-Defined Sensor Dots

Fabian Hader·Jan Vogelbruch·Simon Humpohl·Tobias Hangleiter·Chimezie Eguzo·Stefan Heinen·Stefanie Meyer·Stefan van Waasen

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Abstract

In gate-defined quantum dot systems, the conductance change of electrostatically coupled sensor dots allows the observation of the quantum dots' charge and spin states. Therefore, the sensor dot must be optimally sensitive to changes in its electrostatic environment. A series of conductance measurements varying the two sensor-dot-forming barrier gate voltages serve to tune the dot into a corresponding operating regime. In this paper, we analyze the noise characteristics of the measured data and define a criterion to identify continuous regions with a sufficient signal-gradient-to-noise ratio. Hence, accurate noise estimation is required when identifying the optimal operating regime. Therefore, we evaluate several existing noise estimators, modify them for 1D data, optimize their parameters, and analyze their quality based on simulated data. The estimator of Chen et al. turns out to be best suited for our application concerning minimally scattering results. Furthermore, using this estimator in an algorithm for flank-of-interest classification in measured data shows the relevance and applicability of our approach.

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Fabian Hader, Jan Vogelbruch, Simon Humpohl, Tobias Hangleiter, Chimezie Eguzo, Stefan Heinen, Stefanie Meyer, Stefan van Waasen. 2025-08-11. On Noise-Sensitive Automatic Tuning of Gate-Defined Sensor Dots. https://doi.org/10.1109/tqe.2023.3255743

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