Topological Quantum Properties of Chiral Crystals

ORAL

Abstract

Chiral crystals are materials whose lattice structure with a well-defined handedness due to the lack of inversion, mirror, or other roto-inversion symmetries, which represent a broad, important class of quantum materials. Yet, the topological properties of chiral crystals have still remained largely uncharacterized. Here, we show that Kramers-Weyl fermions are a universal topological electronic property of chiral crystals with spin-orbit coupling (SOC). Unlike conventional Weyl fermions, they appear at time-reversal-invariant momenta. By combining our analysis with the results of previous works, we further determine that all point-like nodal degeneracies in nonmagnetic chiral crystals with relevant SOC carry nontrivial Chern numbers. Using this theory, we identify representative chiral materials in 33 of the 65 chiral space groups in which topological chiral fermions are relevant to low-energy physics. Among all the materials, RhSi family exhibit the ideal topological band structures with longest Fermi arcs and nontrivial energy windows.
[1] Nat. Mater. 17, 978–985
[2] Phys. Rev. Lett. 119, 206401

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Presenters

  • Guoqing Chang

    Department of Physics, Princeton University, Princeton University, Physics, Princeton U.

Authors

  • Guoqing Chang

    Department of Physics, Princeton University, Princeton University, Physics, Princeton U.

  • Benjamin J. Wieder

    Princeton University

  • Frank Schindler

    University of Zurich

  • Titus Neupert

    University of Zurich, Physics, University of Zurich, Physik Institut, University of Zurich

  • Suyang Xu

    Department of Physics, Massachusetts Institute of Technology, Massachusetts Institute of Technology, MIT, Physics, MIT, Department of Physics, Massachusetts Institute of Technology, Cambridge

  • 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

  • Zahid Hasan

    Department of Physics, Princeton University, Princeton University, Laboratory for Topological Quantum Matter & Advanced Spectroscopy, Princeton University, Physics, Princeton U.