Understanding chemical bonding in adatom configurations on the surface of the magnetic Weyl semi-metal Co<sub>3</sub>Sn<sub>2</sub>S<sub>2</sub> with machine learning, 3D scanning tunneling spectroscopy, and first-principles calculations

ORAL

Abstract

The cleaved surface of the magnetic Weyl semi-metal Co3Sn2S2 offers an ideal testing ground for understanding the chemical bonding of various adatom configurations that remain after cleavage. Changes in local electronic tunneling spectra can reveal different chemical bonding states of the adatoms, however deciphering these sometimes, subtle, changes are not straightforward. In fact, the elemental composition of the adatoms themselves has recently been under debate by several groups1,2. Here we develop a machine learning workflow that combines supervised learning in the spatial domain and unsupervised learning in the energy domain that, with direct comparison to first-principles calculations performed in-tandem, allows an enhanced understanding of the elemental composition and chemical bonding nature of the adatoms and their configurations. Our findings indicate that adatoms belonging to the same structural configuration differ in electronic structure, implying a difference in chemical bonding and possibly elemental composition, paving the way towards a more complete understanding the surface of this unique material.

1. Yin, J.-X. et al. Nature Physics 15, 443–448 (2019).
2. Morali, N. et al. Science 365, 1286–1291 (2019).

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Presenters

  • Kevin Roccapriore

    • Oak Ridge National Lab

Authors

  • Kevin Roccapriore

    • Oak Ridge National Lab

  • Qiang Zou

    • Oak Ridge National Lab

  • Rui Xue

    • Physics and Astronomy, University of Tennessee
    • University of Tennessee
    • Materials Science and Engineering, University of Tennessee, Knoxville

  • Maxim Ziatdinov

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory

  • Mingming Fu

    • Oak Ridge National Lab

  • David George Mandrus

    • Materials Science and Technology Division, Oak Ridge National Labratory
    • Materials Science and Engineering, University of Tennessee
    • Department of Materials Science and Engineering, University of Tennessee
    • University of Tennessee
    • Department of Materials Science and Engineering, University of Tennessee Knoxville
    • Department of Materials Science & Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
    • Oakridge National Laboratory
    • Materials Science and Engineering, University of Tennessee, Knoxville
    • Oak Ridge National Laboratory
    • University of Tennessee - Knoxville
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Department of Physics, University of Tennessee Knoxville
    • Materials Science and Technology, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory, Materials Science and Technology Division
    • Department of Materials Science, The University of Tennessee
    • University of Tennessee, Knoxville

  • Mina Yoon

    • Center for Nanophase Materials Sciences, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory, USA
    • Oak Ridge National Lab
    • CNMS, Oak Ridge National Lab

  • Bobby G Sumpter

    • Oak Ridge National Lab

  • Zheng Gai

    • Oak Ridge National Laboratory
    • Oak Ridge National Lab

  • Sergei Kalinin

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory