Effect of magnetic tunneling layer in van der Waals Josephson Junction

ORAL

Abstract

Van der Waals (vdW) material has been attracted much attention recently because of their unique features including the accessibility to atomically thin and flat single-crystalline heterostructure. The two-dimensional (2D) nature of these heterointerfaces often enhances the quantum effect. Here, we report vdW ferromagnet can provide a unique opportunity to study the interplay of superconductivity and magnetism. We fabricated a ferromagnetic tunneling device consisting of vdW ferromagnet and superconductor. We observed that the devices exhibit Josephson coupling through magnetic tunneling across 1-6 atomic unit cell thick ferromagnetic insulating layers. Our observation is in contrast with the lack of Josephson coupling reported across traditional ferromagnetic insulating materials such as EuS. We also observed that our superconductor/ferromagnet hybrid devices show the hysteretic critical current against magnetic field sweep. The observed hysteresis differs from the one expected from the coercive field of the ferromagnet. Further study on magnetic structure and switching current distribution indicates the observed phenomena arisen from the interplay between magnetic domain and superconducting vortex structures.

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Presenters

  • Hiroshi Idzuchi

    Tohoku University(IMRAM) and RIKEN(CEMS)

Authors

  • Hiroshi Idzuchi

    Tohoku University(IMRAM) and RIKEN(CEMS)

  • Ken Harada

    CEMS, RIKEN

  • Ko-Fan Huang

    Harvard University, Physics department, Harvard University

  • Na Hyun Jo

    Iowa State University, Iowa State University and Ames Laboratory, Ames Laboratory and Department of Physics & Astronomy, Iowa State University, Ames, IA 50010, USA, Department of Physics & Astronomy, Iowa State University, Department of Physics and Astronomy, Iowa State University, Department of physics and astronomy, Iowa State University/Ames Laboratory, Physics, Iowa State University/Ames Laboratory

  • Daisuke Shindo

    Tohoku University(IMRAM) and RIKEN(CEMS)

  • Paul Canfield

    Ames Laboratory and Dept. of Physics, Iowa State University, Ames Laboratory, U.S. DOE, Iowa State University, Ames, Iowa 50011, USA., Ames Laboratory, Iowa State University, Department of Physics, Iowa State University, Ames Laboratory, Ames, Iowa 50011, USA, Ames Laboratory, Iowa State University, Ames Laboratory/Iowa State University, Iowa State University and Ames Laboratory, Ames Laboratory and Iowa State University, Ames, IA, USA, Ames Laboratory and Dept. of Phys. and Astro.,, Iowa State Univ., Ames Laboratory and Department of Physics & Astronomy, Iowa State University, Ames, IA 50010, USA, Ames Lab & Dept of Physics and Astronomy, Iowa State University, Department of Physics & Astronomy, Iowa State University, Department of physics and astronomy, Iowa State University/Ames Laboratory, Physics, Iowa State University/Ames Laboratory, Ames Laboratory & Iowa State University, Physics, Iowa State University

  • Philip Kim

    Harvard University, Department of Physics, Harvard University & School of Engineering and Applied Sciences, Harvard University, Department of Physics, Harvard University, Cambridge, MA 02138, USA., Physics, Harvard University, Physics and Applied Physics, Harvard University, Physics department, Harvard University