Dirac Line-nodes and Effect of Spin-orbit Coupling in Non-symmorphic Critical Semimetal <i>M</i>SiS (<i>M</i>=Hf, Zr)

ORAL

Abstract

Topological Dirac semimetals (TDSs) represent a new state of quantum matter recently discovered that offers a platform for realizing many exotic physical phenomena. A TDS is characterized by the linear touching of bulk bands at discrete points in the momentum space (i.e. 3D Dirac points), such as in Na3Bi and Cd3As2. More recently, new types of Dirac semimetals with robust Dirac line-nodes have been proposed that extends the bulk linear touching from discrete points to 1D lines. In this work, using angle-resolved photoemission spectroscopy (ARPES), we explored the electronic structure of the non-symmorphic crystals MSiS (M=Hf, Zr). Remarkably, by mapping out the band structure in the full 3D Brillouin Zone (BZ), we observed two sets of Dirac line-nodes in parallel with the kz–axis and their dispersions. Interestingly, along directions other than the line-nodes in the 3D BZ, the bulk degeneracy is lifted by spin-orbit coupling (SOC) in both compounds with larger magnitude in HfSiS. Our work not only experimentally confirms a new Dirac line-node semimetal family protected by non-symmorphic symmetry, but also helps understanding and further exploring the exotic properties as well as practical applications of the MSiS family of compounds.

–

Presenters

  • Cheng Chen

    • physics, university of oxford

Authors

  • Cheng Chen

    • physics, university of oxford

  • Xiang Xu

    • Tsinghua university

  • Juan Jiang

    • Oxford Unv.
    • Lawrence Berkeley National Lab
    • Lawerence Berkeley National Lab

  • Shu-Chun Wu

    • Max Planck Institute
    • Max Planck Institute for Chemical Physics of Solids

  • yanpeng qi

    • Max Planck Institute
    • Max Planck Institute for Chemical Physics of Solids

  • LeXian Yang

    • Tsinghua university

  • Meixiao Wang

    • ShanghaiTech University
    • Physics and Astronomy, Shanghai Jiao Tong Univ
    • Shanghai Tech University

  • Yan Sun

    • Max-Planck-Institute for Chemical Physics of Solids
    • Max Planck Institute
    • Max Planck Institute for Chemical Physics of Solids

  • Niels Schroeter

    • physics, university of oxford
    • Department of Physics, University of Oxford

  • haifeng yang

    • Shanghai Tech University

  • Leslie Schoop

    • Department of Chemistry, Princeton University
    • Max Planck Institute for Solid State Research
    • Chemistry, Princeton University
    • Max Planck Institute

  • yangyang Lv

    • Nanjing University

  • jian zhou

    • National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and Collaborative Innovation Center of Advanced Microstructures, Nanjing Unive
    • Nanjing University

  • yanbin chen

    • Nanjing University

  • shuhua yao

    • Nanjing University

  • Ming-Hui Lu

    • Nanjing University

  • Yang-Fang Chen

    • Nanjing University

  • Claudia Felser

    • Max Planck CPfS Dresden
    • MPG
    • Max Planck Institute
    • Max Planck Inst
    • Max Planck Institute for Chemical Physics of Solids

  • Binghai Yan

    • Weizmann Institute of Science
    • Max Planck Institute
    • Max Planck Institute for Chemical Physics of Solids

  • Zhongkai Liu

    • Shanghai Tech University

  • Yulin Chen

    • Physics department, University of Oxford
    • University of Oxford
    • Oxford Unv.
    • physics, university of oxford
    • Department of Physics, University of Oxford
    • Condensed Matter Physics, University of Oxford