Enhanced Superconductivity and Suppression of Charge-density Wave Order in 2H-TaS2 in the Two-dimensional Limit

ORAL

Abstract

As superconductors are thinned down to the 2D limit, their critical temperature Tc typically decreases. Here we report the opposite behavior, an enhancement of Tc with decreasing thickness, in the 2D crystalline superconductor 2H-TaS2. Remarkably, in the monolayer limit, Tc increases by over a factor of four compared to bulk crystals. Accompanying this trend in superconductivity, we observe progressive weakening and suppression of the charge-density wave (CDW) transition with decreasing thickness. To explain these trends, we perform electronic structure calculations showing that a reduction of the CDW amplitude results in a substantial increase of the density of states at the Fermi energy, which contributes to the enhancement of Tc.
Our results provide insights into superconductivity, CDW order, and their mutual interaction in reduced dimensions.

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Presenters

  • Yafang Yang

    Department of Physics, Massachusetts Institute of Technology, Massachusetts Inst of Tech-MIT

Authors

  • Yafang Yang

    Department of Physics, Massachusetts Institute of Technology, Massachusetts Inst of Tech-MIT

  • Shiang Fang

    Department of Physics, Harvard University, Harvard University

  • Valla Fatemi

    Massachusetts Inst of Tech-MIT, Massachusetts Institute of Technology

  • Jonathan Ruhman

    Massachusetts Inst of Tech-MIT, Condensed matter theory , Massachusetts Inst of Tech-MIT, Physics, Massachusetts Institute of Technology

  • Efren Navarro-Moratalla

    Massachusetts Institute of Technology, Instituto de Ciencia Molecular, Universidad de Valencia

  • 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

  • Efthimios Kaxiras

    Department of Physics, Harvard University, Harvard Univ, Harvard University, Physics, Harvard University, School of Engineering and Applied Science, Harvard University

  • Pablo Jarillo-Herrero

    Massachusetts Inst of Tech-MIT, Department of Physics, Massachusetts Institute of Technology, Physics, MIT, MIT, Massachusetts Institute of Technology