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Shadowing of epitaxial superconductors on selectively grown in-plane semiconductor wires for advanced quantum devices

ORAL

Abstract

In superconductor-semiconductor systems, a clean interface between superconductor and semiconductor is crucial for quantum transport studies. Advances in epitaxial Al growth on low-dimensional semiconductors have resulted in enhanced features of superconducting proximity effect. In addition, development of clean junctions by in-situ shadowing has led to further improvement of superconducting features in 1D nanowire-based systems. Here we demonstrate a shadowing scheme of epitaxial superconductors on in-plane quantum wires by selective-area growth. Shadow wall structures are pre-fabricated next to wire-shape trenches. After epitaxial growth of semiconductor wires on the trenches, Al deposition is carried out at an angle between 40 and 60 degrees from the normal direction of the substrate. The shadowing of Al results in clean Al-semiconductor junctions based on the shape of the shadow wall structures. This shadow scheme can be applied to any selective-area growth wires by various techniques such as molecular beam epitaxy, chemical beam epitaxy, and metalorganic vaporphase epitaxy. We further discuss transport studies in devices prepared by this scheme as well as deposition of another superconductor with a higher superconducting transition temperature.

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Presenters

  • Joon Sue Lee

    California Nano-Systems Institute, Univ. of California, Santa Barbara, CA, USA, University of Tennessee Knoxville, Univ of California, Santa Barbara, Physics & Astronomy, Seoul National University, University of California Santa Barbara, California Nanosystems Institute, University of California Santa Barbara, University of California, Santa Barbara

Authors

  • Joon Sue Lee

    California Nano-Systems Institute, Univ. of California, Santa Barbara, CA, USA, University of Tennessee Knoxville, Univ of California, Santa Barbara, Physics & Astronomy, Seoul National University, University of California Santa Barbara, California Nanosystems Institute, University of California Santa Barbara, University of California, Santa Barbara

  • Mihir Pendharkar

    Dept. of Electrical Engineering, Univ. of California, Santa Barbara, CA, USA, IEE, UC Santa Barbara, University of California Santa Barbara, Univ of California, Santa Barbara, Electrical and Computer Engineering, University of California Santa Barbara, Electrical & Computer Engineering, University of California, Santa Barbara, University of California, Santa Barbara

  • connor dempsey

    Dept. of Electrical Engineering, Univ. of California, Santa Barbara, CA, USA, IEE, UC Santa Barbara, University of California Santa Barbara

  • Sukgeun Choi

    Dept. of Electrical Engineering, Univ. of California, Santa Barbara, CA, USA, Univ. of California, Santa Barbara, Electrical and Computer Engineering Department, University of California, Santa Barbara, University of California Santa Barbara

  • Aranya Goswami

    Dept. of Electrical Engineering, Univ. of California, Santa Barbara, CA, USA, Electrical and Computer Engineering Department, University of California, Santa Barbara, University of California Santa Barbara

  • Hao Wu

    University of Pittsburgh, Physics, Univ. of Pittsburgh

  • Po Zhang

    University of Pittsburgh, Physics, Univ. of Pittsburgh

  • Roy Op het Veld

    Dept. of Physics, Technical University, Eindhoven, The Netherlands, Eindhoven University of Technology, Applied Physics, Eindhoven Univ. of Technology, TU Eindhoven, Department of Applied Physics, Eindhoven University of Technology

  • Erik Bakkers

    Dept. of Physics, Technical University, Eindhoven, The Netherlands, Eindhoven University of Technology, Department of Applied Physics, Eindhoven University of Technology, Applied Physics, Eindhoven Univ. of Technology, TU Eindhoven, Applied Physics, Eindhoven University of Technology

  • Sergey M Frolov

    Dept. of Physics, Univ. of Pittsburgh, Pittsburgh, PA, USA, Univ of Pittsburgh, University of Pittsburgh, Physics, Univ. of Pittsburgh

  • Chris J Palmstrom

    Materials Department, University of California, Santa Barbara, UCSB, Departments of Electrical and Computer Engineering and Materials, University of California, Santa Barbara, Dept. of Electrical Engineering, Univ. of California, Santa Barbara, CA, USA, Univ. of California, Santa Barbara, Electrical and Computer Engineering Department, University of California, Santa Barbara, University of California, Santa Barbara, IEE, UC Santa Barbara, University of California Santa Barbara, Univ of California, Santa Barbara, Electrical and Computer Engineering, University of California Santa Barbara, Materials and Electrical & Comp. Eng, University of California, Santa Barbara