Electronic structure and topology across T<sub>c</sub> in the magnetic Weyl semimetal Co<sub>3</sub>Sn<sub>2</sub>S<sub>2</sub>

ORAL

Abstract

Half-metallic ferromagnet Co3Sn2S2 was recently predicted and experimentally confirmed to host topological Weyl points just above the Fermi energy. Using a combination of tight binding models and first principles calculations, we present an analysis of the electronic structure and magnetism in this material. We argue that Co3Sn2S2 evolves from a Mott ferromagnet below the Curie temperature (Tc = 177K) to a correlated metallic state above Tc. We show how the magnetism in Co3Sn2S2 can be represented using a tight-binding model consisting of Co-3dx2-y2 orbitals on the kagome lattice. At an electron filling of 5/6, this model reproduces the experimentally observed magnetism and results in a reduction of the Coulomb interaction due to cluster effects. This reduced value of Hubbard U leads to the Hubbard bands collapsing into a single quasiparticle band across the magnetic transition, creating a correlated metallic state. The consequences of this complex magnetic transition for the topology in this material are discussed with the aid of first principles calculations of the correlated system.

*This research was supported by UC Davis Startup funds, Alfred P. Sloan Foundation (FG-2019-12170), NSF DMR Grant No. 1832728, UC Lab Fees Research Program (LFR-20-653926), and used the Advanced Light Source under contract no. DE-AC02-05CH11231.

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Publication: Rossi, A., Ivanov, V., Sreedhar, S., Gross, A., Shen, Z., Rotenberg, E., Bostwick, A., Jozwiak, C., Taufour, V., Savrasov, S., & Vishik, I. (2021). Electronic structure and topology across Tc in the magnetic Weyl semimetal Co3Sn2S2. Phys. Rev. B, 104, 155115.

Presenters

  • Vsevolod M Ivanov

    • Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory

Authors

  • Antonio Rossi

    • Lawrence Berkeley National Laboratory

  • Vsevolod M Ivanov

    • Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory

  • Sudheer Sreedhar

    • University of California, Davis
    • University of California Davis

  • Adam Gross

    • University of California, Davis
    • University of California Davis

  • Zihao Shen

    • University of California, Davis
    • Univ of California Davis

  • Eli Rotenberg

    • Lawrence Berkeley National Laboratory

  • Aaron Bostwick

    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Lab
    • E. O. Lawrence Berkeley National Laboratory
    • lawrence berkeley lab
    • Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley

  • Christopher Jozwiak

    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Lab
    • E. O. Lawrence Berkeley National Laboratory
    • lawrence berkeley lab
    • Advanced Light Source, Lawrence Berkeley National Laboratory

  • Valentin Taufour

    • University of California, Davis
    • University of California Davis

  • Sergey Y Savrasov

    • University of California, Davis
    • University of California Davis

  • Inna Vishik

    • University of California, Davis