Superconductor-Semiconductor Devices with 2D Holes in Germanium

ORAL

Abstract

The coupling of superconductors to semiconductors receives widespread interest due to their potential for realizing topological superconductivity, interferometers and Andreev Bound State devices [1, 2]. The quality of the induced gap, heavily influenced by the transparency of the superconductor-semiconductor interface, presents a crucial challenge for realizing such devices.
Here, we study proximity induced superconductivity in germanium quantum wells coupled to aluminium. The presence of strong spin-orbit interaction, tunable g-factor and high mobility make germanium an attractive semiconducting platform. Combined with the ease of ohmic contact formation due to Fermi level pinning, Ge-Al is a promising material system for hybrid semiconductor-superconductor devices. We achieved transparencies of 65% and ICRN products of up to 50µV, about three times higher than previously reported [3, 4].
[1] R. M. Lutchyn et al., Phys. Rev. Lett. 105, 077001 (2010).
[2] J.-D. Pillet et al., Nature Physics 6, 965 (2010).
[3] N. W. Hendrickx et al., Phys. Rev. B 99, 075435 (2019)
[4] F. Vigneau et al., Nano Lett. 19, 1023-1027 (2019)

*The project received financial support from NOMIS foundation.

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Presenters

  • Kushagra Aggarwal

    • Institute of Science and Technology Austria

Authors

  • Kushagra Aggarwal

    • Institute of Science and Technology Austria

  • Andrea Hofmann

    • Institute of Science and Technology Austria

  • Daniel Jirovec

    • Institute of Science and Technology Austria

  • Ivan Prieto Gonzalez

    • Institute of Science and Technology Austria

  • Amir Sammak

    • Netherlands Organization for Applied Scientific Research (TNO)
    • QuTech, Delft University of Technology

  • Menno Veldhorst

    • Delft University of Technology
    • QuTech and Kavli Institute of Nanoscience
    • University of Twente
    • QuTech, Delft University of Technology
    • Delft University of Technology, Delft, The Netherlands

  • Giordano Scappucci

    • Delft University of Technology
    • QuTech and Kavli Institute of Nanoscience
    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology
    • QuTech, Delft University of Technology
    • Delft University of Technology, Delft, The Netherlands

  • Georgios Katsaros

    • Institute of Science and Technology Austria