Single-hole pump in germanium

Rossi, Alessandro and Hendrickx, Nico W and Sammak, Amir and Veldhorst, Menno and Scappucci, Giordano and Kataoka, Masaya (2021) Single-hole pump in germanium. Journal of Physics D: Applied Physics, 54 (43). 434001. ISSN 0022-3727 (https://doi.org/10.1088/1361-6463/ac181d)

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Abstract

Abstract: Single-charge pumps are the main candidates for quantum-based standards of the unit ampere because they can generate accurate and quantized electric currents. In order to approach the metrological requirements in terms of both accuracy and speed of operation, in the past decade there has been a focus on semiconductor-based devices. The use of a variety of semiconductor materials enables the universality of charge pump devices to be tested, a highly desirable demonstration for metrology, with GaAs and Si pumps at the forefront of these tests. Here, we show that pumping can be achieved in a yet unexplored semiconductor, i.e. germanium. We realise a single-hole pump with a tunable-barrier quantum dot electrostatically defined at a Ge/SiGe heterostructure interface. We observe quantized current plateaux by driving the system with a single sinusoidal drive up to a frequency of 100 MHz. The operation of the prototype was affected by accidental formation of multiple dots, probably due to disorder potential, and random charge fluctuations. We suggest straightforward refinements of the fabrication process to improve pump characteristics in future experiments.

  • Item type:Article
    ID code:77296
    Dates:
    Date
    Event
    28 October 2021
    Published
    27 July 2021
    Published Online
    27 July 2021
    Accepted
    Subjects:Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:04 Aug 2021 15:06
    Last modified:09 Apr 2024 02:34
    URI:https://strathprints.strath.ac.uk/id/eprint/77296
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