Metallic ground state in an ion-gated two-dimensional superconductor

ORAL

Abstract

Ever since a discovery of insulator-superconductor transition in metallic thin films, the ground state of clean two-dimensional (2D) superconductors has been a long standing fundamental question. Recently emerging electric double layer transistors enabled researchers to realize electric-field-induced superconductivity in various substances, which provides us with new opportunities to investigate the ground state of 2D superconductivity. In this presentation, we report that the majority of the field-temperature phase diagram of electric-field-induced superconductivity in ZrNCl including T = 0 K is occupied by a metallic state with finite resistance due to the quantum tunneling of isolated vortices and flux flow caused by extreme two-dimensionality and weak pinning potential. These results imply that electric-field-induced superconductivity can be an ideal platform for accessing quantum vortex states in clean 2D superconductors.

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Authors

  • Yu Saito

    • Quantum-Phase Electronics Center (QPEC) and Department of Applied Physics, The University of Tokyo, Japan
    • Univ. of Tokyo

  • Yu Saito

    • QPEC and Department of Applied Physics, The University of Tokyo, Japan

  • Yuichi Kasahara

    • Department of Physics, Kyoto University, Japan

  • Jianting Ye

    • Zernike Institute for Advanced Materials, University of Groningen, The Netherlands

  • Tsutomu Nojima

    • Institute for Materials Research, Tohoku University, Japan