Type-II Symmetry-Protected Topological Dirac Semimetals

ORAL

Abstract

The recent proposal of the type-II Weyl semimetal state has attracted significant interest. In this work, we propose the concept of the three-dimensional type-II Dirac fermion and theoretically identify this new symmetry-protected topological state in the large family of VAl3 family (VAl3, Nb Al3, TaAl3, NbGa3, and TaGa3). We show that the VAl3 family features a pair of strongly Lorentz-violating type-II Dirac nodes and that each Dirac node can be split into four type-II Weyl nodes with chiral charge ±1 via symmetry breaking. Furthermore, we predict that the Landau level spectrum arising from the type-II Dirac fermions in VAl3 is distinct from that of known Dirac or Weyl semimetals. We also demonstrate a topological phase transition from a type-II Dirac semimetal to a quadratic Weyl semimetal or a topological crystalline insulator via crystalline distortions [1].

[1] T.-R. Chang et al., Phys. Rev. Lett. 119, 026404 (2017)

–

Presenters

  • Tay-Rong Chang

    • Physics, National Cheng Kung University
    • National Cheng Kung University
    • Department of Physics, National Tsing Hua University
    • Natl Cheng Kung U.

Authors

  • Tay-Rong Chang

    • Physics, National Cheng Kung University
    • National Cheng Kung University
    • Department of Physics, National Tsing Hua University
    • Natl Cheng Kung U.

  • Suyang Xu

    • MIT
    • Department of Physics, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology
    • Princeton University
    • Princeton U.
    • Massachusetts Inst of Tech-MIT

  • Daniel Sanchez

    • Princeton Univ
    • Princeton University
    • Princeton U.

  • Wei-Feng Tsai

    • National U. of Singapore

  • Shin-Ming Huang

    • National Sun Yat-sen University
    • Department of Physics, National Sun Yat-sen University
    • National Sun Yat-Sen University
    • National Sun Yat-Sen U.
    • Department of Physics, National Sun Yat-Sen University
    • Physic, Natl Sun Yat Sen Univ
    • Physics, Natl Sun Yat Sen Univ

  • Guoqing Chang

    • National University of Singapore
    • Institute of Physics, Academica Sinica
    • Institute of Physics, Academia Sinica
    • Princeton Univ
    • National U. of Singapore

  • Chuang-Han Hsu

    • Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore
    • National U. of Singapore

  • Guang Bian

    • Univ of Missouri - Columbia
    • University of Missouri
    • Princeton U.
    • Department of Physics and Astronomy, University of Missouri

  • Ilya Belopolski

    • Princeton Univ
    • Princeton University
    • Princeton U.

  • Zhiming Yu

    • Singapore U. of Tec. and Design
    • Engineering Product Development Pillar, Singapore University of Technology and Design

  • Shengyuan Yang

    • Singapore University of Technology and Design
    • Research Laboratory for Quantum Materials, Singapore University of Technology and Design
    • Singapore U. of Tec. and Design
    • Engineering Product Development Pillar, Singapore University of Technology and Design

  • Titus Neupert

    • University of Zurich
    • Department of Physics, University of Zurich
    • U. of Zurich

  • Horng-Tay Jeng

    • Academia Sinica
    • Department of Physics, National Tsing Hua University
    • Natl Tsing Hua Univ
    • National Tsing Hua University

  • Hsin Lin

    • Academia Sinica
    • National University of Singapore
    • Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore
    • Institute of Physics, Academica Sinica
    • Institute of Physics, Academia Sinica
    • National U. of Singapore
    • Natl Univ of Singapore
    • National University of Signapore

  • Zahid Hasan

    • Princeton Univ
    • Princeton University
    • Princeton U.