Photoemission studies on the 3D Dirac semiemtal state in Na$_3$Bi

ORAL

Abstract

A three-dimensional Dirac semimetal is a novel state of matter that has recently attracted interest in condensed matter physics and materials science. We present electronic structure measurements on the (100) surface of a recently discovered Dirac semimetal material Na$_3$Bi. Our experimental data, for the first time, reveal a Lifshitz transition between the two bulk Dirac cones in the bulk band structure of Na$_3$Bi. These results identify the first example of a band structure singularity in 3D Dirac materials. This is in contrast to its 2D analogs such as in twisted bilayer graphene or the surface states of topological crystalline insulators, which have been studied extensively. The observation of multiple bulk Dirac nodes along the rotational crystal axis away from the Kramers point also serve as a signature for the symmetry-protected nature of the Dirac semimetal state in Na$_3$Bi as elaborated in recent theories.

*The work at Princeton and Princeton-led synchrotron-based ARPES measurements is supported by U.S. DOE DE-FG-02-05ER46200.

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Authors

  • Suyang Xu

    • Department of Physics, Princeton University
    • Princeton University

  • Liu Chang

    • Department of Physics, Princeton University
    • Princeton University

  • Satya K. Kushwaha

    • Princeton University

  • Raman Sankar

    • National Taiwan University
    • National Taiwan University, Taipei

  • Jason W. Krizan

    • Princeton University

  • Ilya Belopolski

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

  • Madhab Neupane

    • Department of Physics, Princeton University
    • Princeton University

  • Guang Bian

    • Department of Physics, Princeton University
    • Princeton University

  • Nasser Alidoust

    • Department of Physics, Princeton University
    • Princeton University

  • Tay-Rong Chang

    • National Tsing Hua U., Taiwan
    • National Tsing Hua University

  • Horng-Tay Jeng

    • National Tsing Hua University

  • Cheng-Yi Huang

    • National Sun Yat-Sen University

  • Wei-Feng Tsai

    • Department of Physics, National Sun Yat-sen University
    • National Sun Yat-sen University, Kaohsiung, Taiwan
    • National Sun Yat-Sen University

  • Hsin Lin

    • National University of Singapore
    • Department of Physics, National University of Singapore

  • Pavel P. Shibayev

    • Princeton University

  • Fang Cheng Chou

    • National Taiwan University
    • National Taiwan University, Taipei

  • Robert J. Cava

    • Department of Chemistry, Princeton University
    • Princeton University

  • Zahid Hasan

    • Department of Physics, Princeton University
    • Princeton University