Observation of topological superconductivity on the surface of iron-based superconductor

ORAL

Abstract

Topological superconductors, whose edge hosts Majorana bound states or Majorana fermions that obey non-Abelian statistics, can be used for low-decoherence quantum computations. Most of the proposed topological superconductors are realized with spin-helical states through proximity effect to BCS superconductors. However, such approaches are difficult for further studies and applications because of the low transition temperatures and complicated hetero-structures. Here by using high-resolution spin-resolved and angle-resolved photoelectron spectroscopy, we discover that the iron-based superconductor FeTe1-xSex (x = 0.45, Tc = 14.5 K) hosts Dirac-cone type spin-helical surface states at Fermi level, which open an s-wave SC gap below Tc. Our study proves that the surface states of FeTe0.55Se0.45 are 2D topologically superconducting, and thus provides a simple and possibly high-Tc platform for realizing Majorana fermions.

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Presenters

  • Peng Zhang

    • Institute for Solid State Physics, University of Tokyo

Authors

  • Peng Zhang

    • Institute for Solid State Physics, University of Tokyo

  • Koichiro Yaji

    • Institute for Solid State Physics, University of Tokyo

  • Takahiro Hashimoto

    • Institute for Solid State Physics, University of Tokyo

  • Yuichi Ota

    • Institute for Solid State Physics, University of Tokyo

  • Takeshi Kondo

    • Institute for Solid State Physics, University of Tokyo

  • Kozo Okazaki

    • Institute for Solid State Physics, University of Tokyo

  • Zhijun Wang

    • Physics, Princeton University
    • Princeton University
    • Department of Physics, Princeton University
    • Physics, Princeton

  • Jinsheng Wen

    • National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University
    • Nanjing Univ
    • Department of Physics, Nanjing University
    • Nanjing University

  • Genda Gu

    • Brookhaven National Laboratory
    • Brookhaven National Labs
    • Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory
    • Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory
    • Condensed Matter &materials Science, Brookhaven Natl Lab
    • Brookhaven Natl Lab
    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Brookhaven Natl. Lab
    • Brookhaven National Lab
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • brookhaven national laboratory

  • Hong Ding

    • Insititute of Physics, Chinese Academy of Scienes (CAS)
    • Institute of Physics, Chinese Academy of Sciences
    • Institute of physics, Chinese Academy of Sciences

  • Shik Shin

    • Institute for Solid State Physics, University of Tokyo