Universal Topological Electronic Properties of Nonmagnetic Chiral Crystals

ORAL

Abstract

Chiral crystals are materials whose lattice structure has a well-defined handedness due to the lack of inversion, mirror, or other roto-inversion symmetries. Their structural chirality has been found to allow a wide range of phenomena, including skyrmions in chiral magnets, unconventional pairing in chiral superconductors, nonlocal transport and unique magnetoelectric effects in chiral metals. We show a universal topological electronic property of all nonmagnetic chiral crystals with spin-orbit coupling. In these materials, the combination of structural chirality and time-reversal symmetry is sufficient to guarantee the presence of two-fold-degenerate chiral fermions at the time-reversal invariant momenta, Kramers-Weyl. We further show that Kramers-Weyl fermions enable a number of unique topological phenomena, including a quantized photogalvanic current, the chiral and gyrotropic magnetic effects and electron spin-momentum locking. Considering the abundance of chiral crystals, our findings are widely applicable. The symmetry-guaranteed presence of these fermions in all chiral crystals provides a new and reliable means of engineering and controlling the unconventional optical, transport, and superconducting properties of chiral materials[1].
1.G. Chang et al., arXiv: 1611.07925

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Presenters

  • Guoqing Chang

    National University of Singapore, Institute of Physics, Academica Sinica, Institute of Physics, Academia Sinica, Princeton Univ, National U. of Singapore

Authors

  • Guoqing Chang

    National University of Singapore, Institute of Physics, Academica Sinica, Institute of Physics, Academia Sinica, Princeton Univ, National U. of Singapore

  • Benjamin Wieder

    Princeton Univ, Department of Physics, Princeton University

  • Frank Schindler

    University of Zurich, Department of Physics, University of Zurich

  • Daniel Sanchez

    Princeton Univ, Princeton University, Princeton U.

  • Ilya Belopolski

    Princeton Univ, Princeton University, Princeton U.

  • Shin-Ming Huang

    National Sun Yat-sen University, Department of Physics, National Sun Yat-sen University, National Sun Yat-Sen University, National Sun Yat-Sen U., Department of Physics, National Sun Yat-Sen University, Physic, Natl Sun Yat Sen Univ, Physics, Natl Sun Yat Sen Univ

  • Bahadur Singh

    National University of Singapore

  • Di Wu

    National University of Singapore

  • Tay-Rong Chang

    Physics, National Cheng Kung University, National Cheng Kung University, Department of Physics, National Tsing Hua University, Natl Cheng Kung U.

  • Titus Neupert

    University of Zurich, Department of Physics, University of Zurich, U. of Zurich

  • Suyang Xu

    MIT, Department of Physics, Massachusetts Institute of Technology, Massachusetts Institute of Technology, Princeton University, Princeton U., Massachusetts Inst of Tech-MIT

  • Hsin Lin

    Academia Sinica, National University of Singapore, Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Institute of Physics, Academica Sinica, Institute of Physics, Academia Sinica, National U. of Singapore, Natl Univ of Singapore, National University of Signapore

  • Zahid Hasan

    Princeton Univ, Princeton University, Princeton U.