A new topological crystalline insulator state in the TaAs2materials class

ORAL

Abstract

Crystalline symmetries drive a variety of topological crystalline insulator (TCI) phases in materials. Here, based on first-principles calculations combined with associated symmetry analysis, we identify a new rotational-symmetry protected TCI state in the TaAs2family of compounds. The low-energy band structure consists of two bulk nodal lines in the absence of spin-orbit coupling (SOC) effects. Turning on the SOC opens a continuous band gap in the spectrum and drives the system into a C2Tsymmetry protected TCI state. On the (010) surface, we show the presence of rotational-symmetry-protected nontrivial Dirac cone states within a local bulk energy gap of 300 meV. Our results indicate that the TaAs2materials family provides an ideal setting for exploring unique physics associated with the rotational-symmetry protected TCIs.

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Presenters

  • Baokai Wang

    Northeastern University, Physics, Northeastern University, Boston, Massachusetts 02115, USA, Department of Physics, Northeastern University

Authors

  • Baokai Wang

    Northeastern University, Physics, Northeastern University, Boston, Massachusetts 02115, USA, Department of Physics, Northeastern University

  • Barun Ghosh

    Physics, Indian Institute of Technology Kanpur,Kanpur 208016, India, Indian Institute of Technology Kanpur, India

  • Wei-Chi Chiu

    Physics, Northeastern University, Boston, Massachusetts 02115, USA, Department of Physics, Northeastern University

  • Bahadur Singh

    SZU-NUS Collaborative Center and International Collaborative Laboratory of 2D Materials for Optoelectronic Science & Technology, Engineering Technology Research Center for 2D, Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA /SZU-NUS Collaborative Center and International Collaborative Laboratory of 2D Materials for, Department of Physics, National University of Singapore, SZU-NUS Collaborative Center and International Collaborative Laboratory of 2D Materials for Optoelectronic Science \& Technology, Engineering Technology Research Center for 2, Department of Physics, Northeastern University, Shenzhen University, Shenzhen, China, College of Optoelectronic Engineering, Shenzhen University

  • Chenliang Su

    SZU-NUS Collaborative Center and International Collaborative Laboratory of 2D Materials for Optoelectronic Science & Technology, Engineering Technology Research Center for 2D, SZU-NUS Collaborative Center and International Collaborative Laboratory of 2D Materials for Optoelectronic Science \& Technology, Engineering Technology Research Center for 2, Shenzhen University, Shenzhen, China, SZU-NUS Collaborative Center and International Collaborative, Laboratory of 2D Materials for Optoelectronic Science & Technology, Engineering Technology Research Center for 2

  • Amit Agarwal

    Physics, Indian Institute of Technology Kanpur,Kanpur 208016, India, Indian Institute of Technology Kanpur, India

  • Hsin Lin

    Academia Sinica, Institute of Physics, Academia Sinica, Physics, Academia Sinica, Taipei 11529, Taiwan, Institute of Physics, Academia Sinica, Taipei 11529, Taiwan, Physics, Academia Sinica, Department of Physics, National University of Singapore, National University of Singapore, Academia Sinica, Taipei, Taiwan

  • Arun Bansil

    Department of Physics, Northeastern University, Northeastern, Physics, Northeastern University, Boston, Massachusetts 02115, USA, Northeastern University, Northeastern University, Boston (MA), USA, Physics, Northeastern U., Department of Physics, Northwestern University, Physics, Northeastern University, Boston, MA, USA