Quantum and classical vortex ratchets in a trigonal 2D superconductor

ORAL

Abstract

One of the unique features of recently emerging 2D superconductors is the quantum metallic state, which is a temperature-independent finite resistive state that appears once finite magnetic field is switched on [1, 2]. This quantum metallic state exhibits a sharp contrast with the conventional superconductor-insulator transition in conventional 2D systems, where the metallic state appears only at a single critical point.
To investigate the vortex dynamics which governs the resistance in the quantum metallic state, we have investigated the nonreciprocal transport in gated MoS2, an archetypal noncentrosymmetric 2D superconductor with trigonal symmetry. We found that the second harmonic resistance Rxx2ω appears when the vortex motion is controlled by the classical vortex flow, while Rxx2ω is substantially suppressed when the vortex motion is in quantum creep region. The present result indicates that the trigonal 2D superconductor is a new model system for investigation of quantum and classical ratchets.
[1] Y. Saito et al., Science. 350, 409–413 (2015).
[2] A. W. Tsen et al., Nat. Phys. 12, 208–212 (2016).

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Presenters

  • Yuki Itahashi

    Department of applied physics, University of Tokyo, Department of Applied Physics, University of Tokyo, University of Tokyo

Authors

  • Yuki Itahashi

    Department of applied physics, University of Tokyo, Department of Applied Physics, University of Tokyo, University of Tokyo

  • Yu Saito

    Department of Applied Physics, University of Tokyo

  • Toshiya Ideue

    University of Tokyo, Department of applied physics, University of Tokyo, Department of Applied Physics, University of Tokyo

  • Tsutomu Nojima

    Tohoku University, Institute for Materials Research, Tohoku University

  • Yoshihiro Iwasa

    Department of Applied Physics, The University of Tokyo, University of Tokyo, Department of applied physics, University of Tokyo, Department of Applied Physics, University of Tokyo, Quantum-Phase Electronics Center and Department of Applied Physics, University of Tokyo