Mapping the spin waves in a bilayer kagome ferromagnet Fe3Sn2 by resonant inelastic X-ray scattering

ORAL

Abstract

Magnetic metals with kagome structure can host various topologically non-trivial spin or electronic states, providing an extraordinary platform for studying the fundamental physicsof quantum materials. The metallic kagome ferromagnet Fe3Sn2, which has large spin-orbital coupling, shows considerable interplay between magnetism and non-trivial electronic states. The material is a host of anomalous bulk properties, including a first-order spin reorientation transition(1), an anomalous planar Hall effect(2), and field tunable electronic states(3, 4). Using the MCD RIXS and XAS (X-ray absorption spectroscopy), we report a flat spin wave band with large (compared to elemental iron) orbital moments in Fe3Sn2(5). The flat mode energy is consistent with the high Curie temperature ( K) as well as the strong acoustic mode dispersion. Our results illustrate how the magnetic circular dichroism analysis enhances the sensitivity of RIXS to magnetic excitations in ferromagnetic materials and unveil an unconventional flat spin wave band in a kagome ferromagnet.

* The experiments were performed at the ADRESS beamline of the Swiss Light Source at the Paul Scherrer Institut (PSI). The experimental work at PSI is supported by the Swiss National Science Foundation through project no. 200021 178867, and the Sinergia Network Mott Physics Beyond the Heisenberg Model (MPBH) (SNSF Research Grants CRSII2 160765/1 and CRSII2 141962). T.C.A. acknowledges funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No.701647 (PSI-FELLOW-II-3i program). G.A. was supported by the European Research Council under the European Union's Horizon 2020 research and innovation programme HERO (Grant agreement No. 810451). Y.X. acknowledges funding from the Innovation Program for Quantum Science and Technology (No. 2021ZD0302802).

–

Publication: 1. K. Heritage et al., Images of a First‐Order Spin‐Reorientation Phase Transition in a Metallic Kagome Ferromagnet. Advanced Functional Materials 30, (2020).
2. N. Kumar, Y. Soh, Y. Wang, J. Li, Y. Xiong, Anomalour Planar Hall Effect in a kagome ferromagnet. arXiv:2005.14237, (2020).
3. M. Yao et al., Switchable Weyl nodes in topological Kagome ferromagnet Fe3Sn2. ArXiv e-prints. 2018.
4. N. Kumar, Y. Soh, Y. Wang, J. Li, X. Y., Tuning the electronic band structure in a kagome ferromagnetic metal via magnetization. Phys Rev B 106, 045120 (2022).
5. W. Zhang et al., Spin waves in a ferromagnetic topological metal. 2023 (https://doi.org/10.48550/arXiv.2302.01457).

Presenters

  • Gabriel Aeppli

    ETH Zurich

Authors

  • Wenliang Zhang

    Paul Scherrer Institut, Paul Sherrer Institut (PSI)

  • Teguh C Asmara

    Paul Scherrer Institute, European XFEL

  • Yi Tseng

    Paul Scherrer Institute

  • Junbo Li

    High Magnetic Field Lab CAS

  • Yimin Xiong

    Anhui University

  • Vladimir N Strokov

    Paul Scherrer Institute, Paul Scherrer Institut

  • Y Soh

    Paul Scherrer Institute

  • Thorsten Schmitt

    Paul Scherrer Institute, PSI, Paul Sherrer Institut (PSI)

  • Gabriel Aeppli

    ETH Zurich