Spin waves in the antiferromagnetic topological insulator MnBi<sub>2</sub>Te<sub>4</sub>

ORAL

Abstract

MnBi2Te4 is proposed to be the first antiferromagnetic (AF) topological insulator (TI). The natural intergrowth of magnetic and TI layers, and the ground state tunability via a magnetic field provide a unique platform for studying the interplay between magnetism and topological electronic states, which give rise to the quantum anomalous Hall effect and axion electrodynamics. Here we present results from our inelastic neutron scattering (INS) study on MnBi2Te4 single crystals, where we determined the strength of the magnetic interactions and anisotropy in the AF state (TN = 24 K). By comparing our INS data to the dynamic spin susceptibility calculated using a linear-response density functional theory, we find that magnetic interactions extending further than the Mn nearest-neighbor distance are necessary to understand the observed spin wave dispersion.

*This work is supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.

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Presenters

  • Bing Li

    • Ames Laboratory, Ames, IA 50011, USA; Iowa State University, Ames IA 50011, USA
    • Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames
    • Ames Laboratory, Ames, IA 50011, USA; Iowa State University, Ames, IA 50011, USA

Authors

  • Bing Li

    • Ames Laboratory, Ames, IA 50011, USA; Iowa State University, Ames IA 50011, USA
    • Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames
    • Ames Laboratory, Ames, IA 50011, USA; Iowa State University, Ames, IA 50011, USA

  • Simon Riberolles

    • Ames Laboratory, Ames, IA 50011, USA
    • Division of Materials Science & Engineering, Ames Laboratory

  • Liqin Ke

    • Ames Laboratory, Ames, IA 50011, USA
    • Ames Laboratory, Iowa State University
    • Ames Laboratory
    • Iowa State University

  • Elijah Gordon

    • Ames Laboratory, Ames, IA 50011, USA
    • Ames Laboratory, Iowa State University

  • Daniel Pajerowski

    • Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Lab
    • Oak Ridge National Laboratory

  • Andreas Kreyssig

    • Ames Laboratory, Ames, IA 50011, USA; Iowa State University, Ames IA 50011, USA
    • Physics and Astronomy, Iowa State University/Ames Laboratory
    • Department of Physics and Astronomy, Iowa State University/Ames Laboratory
    • Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames
    • Ames Laboratory, Ames, IA 50011, USA; Iowa State University, Ames, IA 50011, USA

  • Benjamin Ueland

    • Ames Laboratory, Ames, IA 50011, USA
    • Division of Materials Science & Engineering, Ames Laboratory
    • Ames Laboratory
    • Ames Lab

  • Jiaqiang Yan

    • Materials Science and Engineering, The University of Tennessee
    • Oak Ridge National Lab
    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Lab
    • Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

  • Robert McQueeney

    • Ames Laboratory, Ames, IA 50011, USA; Iowa State University, Ames IA 50011, USA
    • Iowa State University
    • Ames Laboratory, Iowa State University
    • Physics and Astronomy, Iowa State University/Ames Laboratory
    • Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames
    • Ames Laboratory, Ames, IA 50011, USA; Iowa State University, Ames, IA 50011, USA