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Strain induced Kramers-Weyl Fermions

ORAL

Abstract

Kramers-Weyl fermions are recently found to be widely supported in chiral crystals and exhibit many novel properties. However, in achiral crystals due to the presence of mirror or roto-inversion symmetries, Kramers Weyl fermions are often obscured to emerge due to the presence of nodal lines. In this work, we show Kramers-Weyl fermions are easily generated by removing the degeneracy of these nodal lines through strain effects. Remarkably, based on realistic DFT calculations, in the strained Rashba semiconductor BiTeI, we find a single Kramers-Weyl fermion near Fermi energy. Moreover, a strain induced quantized circular photogalvanic effect (CPGE) is further established. Our work paves a way to study the topology, optoelectronics by the tuning the chirality of crystals.

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Presenters

  • Jinxin Hu

    Physics, Hong Kong University of Science and Technology

Authors

  • Jinxin Hu

    Physics, Hong Kong University of Science and Technology

  • Yingming Xie

    Physics, Hong Kong University of Science and Technology, Hong Kong University of Science and Technology, Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China)

  • Cheng-Ping Zhang

    Physics, Hong Kong University of Science and Technology, Hong Kong University of Science and Technology

  • Xi Dai

    Physics, Hong Kong University of Science and Technology, Physics Department, Hong Kong University of Science and Technology, Physics, Hong Kong University of Science of Technology, Hong Kong University of Science and Technology, Physics, The Hong Kong University of Science and Technology

  • Kam Tuen Law

    Physics, Hong Kong University of Science and Technology, Department of Physics, Hong Kong University of Science and Technology, Hong Kong University of Science and Technology, Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China)