APS Logo

Current-phase relation in bilayer graphene/WSe<sub>2</sub> Josephson junction

ORAL

Abstract

The proximity coupling of WSe2 to graphene can create a large spin-orbit interaction (SOI) in graphene. In particular, for bilayer graphene (BLG) encapsulated in WSe2 (WSe2/BLG/WSe2) it was shown that displacement fields can drive a topological phase transition at zero density due to Ising SOI [1]. Here we study the current-phase relation (CPR) of Josephson junctions created in such van der Waals heterostructures.  At zero (in-plane) magnetic field we find that the CPR is largely independent of carrier density and displacement field. However at finite magnetic fields (~ few hundred mT) we observe anomalous CPRs displaying large gate-dependent phase shifts. While phase shifts are in general expected in Josephson junctions with Rashba-type SOI, the effect we observe is significantly larger and cannot be accounted for by existing models.  Furthermore, we find that this effect is absent for WSe2/SLG/WSe2, BLG/WSe2 and trivial BLG JJs, suggesting that it is possibly related to the specific band structure of WSe2/BLG/WSe2.

[1] J. O. Island, X. Cui, C. Lewandowski, J. Y. Khoo, E. M. Spanton, H. Zhou, D. Rhodes, J. C. Hone, T. Taniguchi, K. Watanabe, L. S. Levitov, M. P. Zaletel, and A. F. Young, Nature 571, 85 (2019).

–

Presenters

  • Prasanna K Rout

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands

Authors

  • Prasanna K Rout

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands

  • Nikos Papadopoulos

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands

  • Mate Kedves

    Budapest University of Technology and Economics and Nanoelectronics "Momentum" Research Group of the Hungarian Academy of Sciences, Budapest, Hungary

  • Kenji Watanabe

    National Institute for Materials Science, Tsukuba, Japan, National Institute for Materials Science, NIMS, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan., Research Center for Functional Materials, National Institute for Materials Science, Advanced, Materials Laboratory, NIMS, 3 National Institute for Materials Science, Tsukuba, Japan, National Institute for Materials Science; 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan, National Institute of Materials Science, Tsukuba, Japan, National Institute of Materials Science, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute for Materials Science (Japan), National Institute for Materials Science, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, Research Center for Functional Materials, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan, Research Center for Functional Materials, National Institute for Materials Science, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science, Japan, National Institute for Material Science, National Institute of Material Sciences, Japan, NIMS, Tsukuba, 2National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan., National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan, National Institute for Materials Science Japan, NIMS, Japan, nims, National Institute for Materials Science, Research Center for Functional Materials, Japan, National Institute for Materials Science Tsukuba, National Institute for Materials Science, 1-1 Namiki, National Institute for Materials Science of Japan, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, NIMS - National Institute for Material Science, Japan, Research Center for Functional Materials, National Institute for Material Science, Tsukuba, Ibaraki, 305-0044, Japan., National Institute for Material Science, Tsukuba, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan, National Institute for Materials Science (NIMS), National Institute for Materials Science, Research Center for Functional Materials, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan, National Institute of Material Science, Kyoto Univ, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan

  • Takashi Taniguchi

    National Institute for Materials Science, Tsukuba, Japan, National Institute for Materials Science, NIMS, Kyoto Univ, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Ibaraki 305-0044, Japan., 3 National Institute for Materials Science, Tsukuba, Japan, National Institute for Materials Science; 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan, National Institute of Materials Science, Tsukuba, Japan, National Institute of Materials Science, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute for Materials Science (Japan), International Center for Materials Nanoarchitectonics, National Institute for Materials Science, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, Kyoto University, International Center for Materials Nanoarchitectonics, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Japan, International Center for Materials Nanoarchitectonics, National Institute for MaterialsScience, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science, Japan, National Institute for Material Science, National Institute of Material Sciences, Japan, NIMS, Tsukuba, 2National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan., National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan, National Institute for Materials Science, Japan, International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan., NIMS, Japan, National Institute for Materials Science (NIMS), NIMS. Japan, International Center for Material Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan, International Center for Material Nanoarchitectonics, National Institute for Materials Science, National Institute for Materials Science Tsukuba, National Institute for Materials Science, 1-1 Namiki, National Institute for Materials Science of Japan, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, NIMS - National Institute for Material Science, Japan, International Center for Materials Nanoarchitectonics, National Institute for Material Science, Tsukuba, Ibaraki 305-0044, Japan., National Institute for Material Science, Tsukuba, National Institute for Materials Science, International Center for Materials Nanoarchitectonics, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan, National Institute of Material Science, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan

  • Peter Makk

    Budapest University of Technology and Economics and Nanoelectronics "Momentum" Research Group of the Hungarian Academy of Sciences, Budapest, Hungary

  • Srijit Goswami

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands, Delft University of Technology