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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