Saddle-point Van Hove singularity in the topological surface states of Pt<sub>2</sub>HgSe<sub>3</sub>

ORAL

Abstract

Saddle-point Van Hove singularities in the topological surface states are interesting because they can provide a new pathway for accessing exotic correlated phenomena in topological materials. Here, based on first-principles calculations combined with a kp model Hamiltonian analysis, we show that the layered platinum mineral jacutingaite (Pt2HgSe3) harbors saddlelike topological surface states with associated Van Hove singularities [1]. Pt2HgSe3 is shown to host two distinct types of nodal lines without spin-orbit coupling (SOC), which are protected by combined inversion (I) and time-reversal (T ) symmetries. Switching on the SOC gaps out the nodal lines and drives the system into a topological state with nonzero weak topological invariant Z2 = (0; 001) and mirror Chern number nM = −2. Surface states on the naturally cleaved (001) surface are found to be nontrivial with a unique saddle-like energy dispersion with type II Van Hove singularities. Our results indicate that Pt2HgSe3 is an ideal candidate material for exploring the properties of topological insulators with saddle-like surface states.


[1] B.Ghosh et.al, Physical Review B 100, 235101 (2019)

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Presenters

  • Barun Ghosh

    • Department of Physics, Indian Institute Of Technology Kanpur
    • Department of Physics, Indian Institute of Technology Kanpur, India
    • Department of Physics, Indian Institute of Technology Kanpur

Authors

  • Barun Ghosh

    • Department of Physics, Indian Institute Of Technology Kanpur
    • Department of Physics, Indian Institute of Technology Kanpur, India
    • Department of Physics, Indian Institute of Technology Kanpur

  • Sougata Mardanya

    • Physics, National Cheng Kung University
    • Department of Physics, Indian Institute of Technology Kanpur, India

  • Bahadur Singh

    • Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research
    • Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research
    • Department of Condensed Matter Physics and Material Science, Tata Institute of Fundamental Research
    • Tata Institute of Fundamental Research
    • Tata Institute for Fundamental Research
    • DCMPMS, Tata Institute of Fundamental Research, India
    • Condensed Matter Physics and Material Science, Tata Institute of Fundamental Research
    • Department of Condensed Matter Physics & Materials Science, Tata Institute of Fundamental Research

  • XIAOTING ZHOU

    • Physics, Northeastern University
    • Department of Physics, Northeastern University, USA

  • Baokai Wang

    • Department of Physics, Northeastern University
    • Northeastern University
    • Department of Physics, Northeastern University, USA

  • Tay-Rong Chang

    • National Cheng Kung University
    • Department of Physics, National Cheng Kung University, Taiwan
    • Physics, National Cheng Kung University

  • Chenliang Su

    • College of Optoelectronic Engineering, Shenzhen University, China

  • Hsin Lin

    • Institute of Physics, Academia Sinica
    • Academia Sinica
    • Institute of Physics, Academia Sinica, Taipei
    • Institute of Physics, Academia Sinica, Taiwan
    • Physics, Academia Sinica

  • Amit Agarwal

    • Department of Physics, Indian Institute Of Technology Kanpur
    • Indian Institute of Technology
    • Department of Physics, Indian Institute of Technology Kanpur, India
    • Department of Physics, Indian Institute of Technology Kanpur

  • Arun Bansil

    • Department of Physics, Northeastern University
    • Northeastern University
    • NU
    • Department of Physics, Northeastern University, USA