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MON: Monday Contributed Sessions

MON 22: Quantum Transport II

MON 22.2: Talk

Monday, September 8, 2025, 16:45–17:00, ZHG104

Transport characteristics of quantum dots for single-electron pumps — •Johannes C. Bayer, Thomas Gerster, Dario Maradan, Niels Ubbelohde, Klaus Pierz, Hans W. Schumacher, and Frank Hohls — Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany

An elegant and direct way to generate accurate currents is given by applying a periodic signal to a tunable barrier quantum dot. Such a device is called a single-electron pump (SEP) and emits a well defined number of n electrons per cycle of an external drive, resulting in a current of I = nef, with elementary charge e and driving frequency f. While individual SEPs can already achieve sub-ppm accuracy [1], the extension to systems operating multiple well-performing SEPs, e.g. in parallel to achieve larger currents, is still challenging. Our SEP devices are based on quantum dots formed electrostatically in a GaAs/AlGaAs two-dimensional electron gas. Based on multiple quantum dot devices, we characterize the DC transport properties and analyze relations to the dynamic SEP operation toward achieving robust, reproducible and scalable devices [2].
[1] F. Stein, et. al., Metrologia 54, S1-S8 (2017).
[2] T. Gerster, et. al., Metrologia 56, 014002 (2019)

Keywords: single-electron pump; quantum dot; 2DEG