Signatures of magnetic Weyl fermion annihilation

ORAL

Abstract

The manipulation of topological states in quantum matter is an essential pursuit of fundamental physics and next-generation quantum technology. Here we report the magnetic manipulation of Weyl fermions in the kagome spin-orbit semimetal Co3Sn2S2, observed by high-resolution photoemission spectroscopy. We demonstrate the exchange collapse of spin-orbit-gapped ferromagnetic Weyl loops into paramagnetic Dirac loops under suppression of the magnetic order. We further observe that topological Fermi arcs disappear in the paramagnetic phase, suggesting the annihilation of exchange-split Weyl points. Our findings indicate that magnetic exchange collapse naturally drives Weyl fermion annihilation, opening new opportunities for engineering topology under correlated order parameters.

*Work at Princeton was supported by the US DOE under the Basic Energy Sciences programme (Grant #: DOE/BES DE-FG-02-05ER46200) and by the Gordon and Betty Moore Foundation (GBMF4547 and GBMF9461; M.Z.H.)

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Publication: Belopolski*, Cochran* et al. arXiv:2105.14034.

Presenters

  • Tyler A Cochran

    • Princeton University

Authors

  • Tyler A Cochran

    • Princeton University

  • Ilya Belopolski

    • RIKEN
    • Princeton University

  • Xiaoxiong Liu

    • Univ of Zurich

  • Zijia Cheng

    • Princeton University
    • Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey, USA.

  • Xian Yang

    • Princeton University

  • Praveen Vir

    • Max Planck Institute for the Chemical Physics of Solids

  • Gohil S Takur

    • Max Planck Institute for the Chemical Physics of Solids

  • Claudia Felser

    • Max Planck Institute for Chemical Physic
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
    • Max Planck Institute for Chemical Physics of Solids

  • Titus Neupert

    • Univ of Zurich
    • University of Zurich
    • University of Zürich

  • Zahid M Hasan

    • Princeton University
    • Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey, USA.