Gate-tunable Josephson diodes for cryogenic memory in magic-angle twisted bilayer graphene

ORAL

Abstract

Superconducting diodes (SDs) exhibit a non-reciprocal supercurrent response. Recently, SDs were reported in graphene-based moiré systems, which offer a promising platform to realize SDs based on Josephson junctions (JJs), since they host various tunable correlated phases [1, 2]. Here, we show gate-defined Josephson diode behavior in magic-angle twisted bilayer graphene, where we tune the weak link of the JJ to the correlated insulator at half-filling of the hole mini-band, reaching diode efficiencies up to 15%. We gain full control over the phase and polarity of the SDs by changing the carrier density of the weak link and the out-of-plane magnetic field. In an underdamped transport regime, we observe distinct hysteretic resistive switching when sweeping the current or magnetic field. This effect can be increased by coupling two gate-defined JJs in series, where we obtain stable hysteretic resistive switching even at zero magnetic field. This finding paves the way for integrating cryogenic memory cells into superconducting quantum devices.

[1] Díez-Mérida et al., Nat. Commun. 14, 2396 (2023)

[2] Lin et al., Nat. Phys. 18, 1221-1227 (2022)

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Presenters

  • Alexander Rothstein

    • 2nd Institute of Physics A, RWTH Aachen University

Authors

  • Alexander Rothstein

    • 2nd Institute of Physics A, RWTH Aachen University

  • Robin J Dolleman

    • 2nd Institute of Physics A, RWTH Aachen University

  • Anthony Achtermann

    • 2nd Institute of Physics A, RWTH Aachen University

  • Frank Volmer

    • AMO GmbH, Advanced Microelectronic Center Aachen (AMICA)

  • Stefan Trellenkamp

    • Helmholtz Nano Facility, Forschungszentrum Juelich GmbH
    • Research Center Jülich

  • Florian Lentz

    • Helmholtz Nano Facility, Forschungszentrum Juelich GmbH

  • Kenji Watanabe

    • National Institute for Materials Science
    • NIMS
    • Research Center for Electronic and Optical Materials, National Institute for Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science

  • Takashi Taniguchi

    • Kyoto Univ
    • National Institute for Materials Science
    • Research Center for Materials Nanoarchitectonics
    • Research Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Sciences
    • NIMS
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science
    • International Center for Materials Nanoarchitectonics, NIMS, Japan
    • International Center for Materials Nanoarchitectonics, Tsukuba
    • National Institue for Materials Science
    • Kyoto University
    • National Institute of Materials Science
    • International Center for Materials Nanoarchitectonics and National Institute for Materials Science

  • Bernd Beschoten

    • 2nd Institute of Physics A, RWTH Aachen University

  • Christoph Stampfer

    • 2nd Institute of Physics A, RWTH Aachen University
    • RWTH Aachen University
    • RWTH Aachen