Observation of linearly dispersive edge modes in a magnetic Weyl semimetal Co<sub>3</sub>Sn<sub>2</sub>S<sub>2</sub>

ORAL

Abstract

The physical realization of Chern insulators is of fundamental and practical interest, as they are predicted to host the quantum anomalous Hall effect (QAHE) and chiral edge states which carry dissipationless current. Realization of the QAHE state has however been challenging due to the complex heterostructures and sub-Kelvin temperatures required. Magnetic Weyl semimetals, essentially stacks of Chern insulators with inter-layer coupling, may provide a new platform for the higher temperature realization of robust 2D QAHE edge states. In this work we present a combined scanning tunneling spectroscopy and theoretical investigation of a newly discovered magnetic Weyl semimetal, Co3Sn2S2. Using numerical simulations we find that chiral edge states can be localized on partially exposed Kagome planes on the surface of a Weyl semimetal. As such, our STM dI/dV maps on narrow kagome Co3Sn terraces show linearly dispersing quantum well-like states, which can be attributed to hybridized chiral edge modes. Our results suggest a new paradigm for studying chiral edge modes in time-reversal breaking Weyl semimetals. More importantly, this work leads a practical route for realizing higher temperature QAHE.

*Basic Energy Sciences DE-SC0014335, Gordon and Betty Moore Foundation Grant GBMF4860

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Presenters

  • Sean Howard

    • Department of Physics, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign
    • Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois Urbana-Champaign

Authors

  • Sean Howard

    • Department of Physics, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign
    • Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois Urbana-Champaign

  • Lin Jiao

    • Department of Physics, University of Illinois at Urbana-Champaign
    • Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois Urbana-Champaign
    • University of Illinois at Urbana-Champaign

  • Zhenyu Wang

    • University of Illinois at Urbana-Champaign
    • UIUC
    • Department of Physics, University of Illinois at Urbana-Champaign
    • Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois Urbana-Champaign

  • Praveen Vir

    • Max Planck Institute For Chemical and Physical Solids
    • Max Planck Institute for Chemical Physics of Solids

  • Chandra Shekhar

    • Max Planck Institute for Chemical Physics of Solids
    • MPI-CPfS Dresden
    • Max Planck Institute For Chemical and Physical Solids

  • Claudia Felser

    • Max Planck Institute for Chemical Physics of Solids
    • MPI-CPfS Dresden
    • Max Planck Institute For Chemical and Physical Solids
    • MPI for chemical physics of solids, Dresden
    • Solid State Chemistry, Max Planck Institute Chemical Physics of Solids
    • Max Planck Institute
    • Max-Planck-Institute for Chemical Physics of Solids , Nöthnitzer Straße-40, 01187 Dresden, Germany
    • Max Planck Inst
    • Max Planck Dresden
    • Chemical Physics of Solids, Max Planck Institute

  • Taylor Hughes

    • Department of Physics and Institute for Condensed Matter Theory, University of Illinois Urbana Champaign
    • Department of Physics and Institute for Condensed Matter Theory, University of Illinois at Urbana-Champaign

  • Vidya Madhavan

    • Physics, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign
    • Department of Physics, University of Illinois at Urbana-Champaign
    • Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois Urbana-Champaign