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Hybrid quantum circuits in vertical magnetic fields

ORAL

Abstract

Topological superconductors, that host Majorana zero modes and parafermions, can also be
realized at the interface of superconductivity and the quantum Hall states in hybrid
superconductor-semiconductor devices. Here, we present (i) two types of artificially
engineered hybrid Josephson circuits fabrication methods, and (ii) sub-Kelvin temperature-
dependent transport measurements at low and high magnetic fields B. We experimentally
demonstrate that the 2D Josephson junctions and field-effect transistors under vertical
magnetic fields show (i) an unusual magnetoconductance oscillations together with
asymmetric dI/dV curves at B < 100 mT, (ii) Superconducting correlation on quantum Hall
states at B up to 6 T, respectively. Our experimental results are qualitatively explained by a
model considering the trivial and topological phase transitions in hybrid 2D Josephson
junctions in vertical fields.
[1] J. Vis. Exp. 150 (e57818) (2019),
[2] Journal of Physics: Conference Series 1182 (1), 012010 (2019),
[3] Journal of Magnetism and Magnetic Materials 459, 282-284 (2018),
[4] IEEE Transactions on Applied Superconductivity 28 (4), 1-4 (2018),
[5] Advanced Materials 29 (37), 1701836 (2017).

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Presenters

  • Kaveh Delfanazari

    Engineering Department & Cavendish Laboratory, University of Cambridge, UK

Authors

  • Kaveh Delfanazari

    Engineering Department & Cavendish Laboratory, University of Cambridge, UK

  • Llorens Serra

    IFISC (UIB-CSIC) and Physics Department, University of the Balearic Islands, Spain

  • Pengcheng Ma

    Cavendish Laboratory, University of Cambridge, UK

  • Ian Farrer

    Department of Electronic and Electrical Engineering, University of Sheffield, UK, Department of Electronic and Electrical Engineering, University of Sheffield, University of Sheffield, Dept. of Electronic & Electrical Engineering, University of Sheffield

  • David A Ritchie

    Cavendish Laboratory, University of Cambridge, UK, Cavendish Laboratory, University of Cambridge, Cambridge University

  • Hannah J Joyce

    Engineering Department, University of Cambridge, UK

  • Michael Joseph Kelly

    Engineering Department & Cavendish Laboratory, University of Cambridge, UK

  • Charles G Smith

    Cavendish Laboratory, University of Cambridge, UK