Superconductivity in Few-layer Stanene

ORAL

Abstract


Superconductivity has been observed in few-layer α-Sn films with thickness down to ~0.72 nm. A BKT-like phase transition behavior as well as distinctly anisotropic upper critical fields have been observed. Furthermore, by varying the thickness of the buffer layer—PbTe(111), thus changing the strain and doping level, we manage to tune the trilayer stanene films from a single-band to a two-band superconductor. This is manifested in the dependence of out-of-plane critical field on critical temperature. A linear response is seen in trilayer stanene grown on 6 layers of PbTe while data points from that on a thicker PbTe demonstrate a concave shape, an archetypical feature of multi-band superconductors. Our in-situ angle-resolved photoemission spectroscopy further reveals that an electron pocket emerges inside the hole band for a trilayer stanene on thicker PbTe substrate. Such an band structure agrees with the theoretically computed energy bands of trilayer stanene in the topological non-trivial phase , indicating that our system could be a topological superconductor.

*This work is financially supported by the Ministry of Science and Technology of China and the National Natural Science Foundation of China.

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Presenters

  • Menghan Liao

    • Department of Physics, Tsinghua University

Authors

  • Menghan Liao

    • Department of Physics, Tsinghua University

  • Yunyi Zang

    • Department of Physics, Tsinghua University

  • Zhaoyong Guan

    • Department of Physics, Tsinghua University

  • Haiwei Li

    • Department of Physics, Tsinghua University

  • Yan Gong

    • Department of Physics, Tsinghua University

  • Kejing Zhu

    • Department of Physics, Tsinghua University
    • Tsinghua University

  • xiaopeng hu

    • Department of Physics, Tsinghua University

  • ding zhang

    • Department of Physics, Tsinghua University
    • Max Planck Institute for Solid State Research

  • Yong Xu

    • Department of Physics, Tsinghua University
    • Tsinghua University

  • Yayu Wang

    • Tsinghua Univ
    • Department of Physics, Tsinghua University

  • Ke He

    • Tsinghua Univ
    • Department of Physics, Tsinghua University
    • Tsinghua University
    • State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University

  • XUCUN MA

    • Tsinghua Univ
    • Physics Department, Tsinghua University
    • Department of Physics, Tsinghua University
    • State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua Univ.

  • Shoucheng Zhang

    • Stanford University
    • Department of Physics, Stanford University
    • Stanford Univ
    • Physics, Stanford University

  • Qikun Xue

    • Physics Department, Tsinghua University
    • Department of Physics, Tsinghua University
    • State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua Univ.
    • Tsinghua University
    • State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University