NbSe<sub>2</sub>–graphene–NbSe<sub>2</sub> Van Der Waals-contacted Planar Josephson Junctions

ORAL

Abstract

Recently, many exotic characteristics of graphene and other cleavable two-dimensional (2D) materials have been investigated extensively. Above all, heterosturctures of those 2D materials built by van der Waals (vdW) coupling reveal assorted novel physical properties and atomically flat clean interfaces [1]. Here, we present our preliminary results on the transport characteristics of graphene planar Josephson junctions (JJs), where NbSe2 was used as a superconducting (SC) electrode material. Graphene–hexagonal-boron-nitride (hBN) bilayer was transferred onto NbSe2 flakes which were closely pre-arranged to make clean interfaces. Entire graphene and NbSe2 flakes are encapsulated by a hBN layer to protect the JJ from chemical contamination during the fabrication processes. The JJ thus fabricated by the chemical-free scheme can lead to enhancing the JJ performance. We characterize the Josephson coupling nature of the junctions by examining the temperature and magnetic field dependence of the junction critical current (Ic) and the SC energy gap (Δ), the size of the IcRN product (RN; normal-state junction resistance) in comparison with the 0 K value of Δ/e.

*Supported by the National Research Foundation through the SRC Center for Topological Matter, POSTECH, Korea (Grant 2011-0030046).

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Presenters

  • Jongyun Lee

    • Pohang Univ of Sci & Tech

Authors

  • Jongyun Lee

    • Pohang Univ of Sci & Tech

  • Minsoo Kim

    • Pohang Univ of Sci & Tech

  • Kenji Watanabe

    • National Institute for Materials Science
    • NIMS
    • National Institute for Material Science
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science (NIMS
    • Advanced Materials Laboratory, NIMS
    • National Institute for Materials Science, Advanced Materials Laboratory
    • National Institue for Materials Science
    • National Institute of Material Science
    • National Institute for Matericals Science
    • Advanced Materials Laboratory
    • National Institute for Materials Science, 1-1 Namiki
    • Advanced materials laboratory, National institute for Materials Science
    • NIMS-Japan

  • Takashi Taniguchi

    • National Institute for Materials Science
    • NIMS
    • National Institute for Material Science
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science (NIMS
    • Advanced Materials Laboratory, NIMS
    • National Institute for Materials Science, Advanced Materials Laboratory
    • National Institue for Materials Science
    • National Institute of Material Science
    • National Institute for Matericals Science
    • Advanced Materials Laboratory
    • National Institute for Materials Science, 1-1 Namiki
    • NIMS-Japan

  • Hu-Jong Lee

    • Pohang Univ of Sci & Tech
    • POSTECH