Magnon-phonon interactions from first principles
Creators
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1.
California Institute of Technology
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2.
University of Valencia
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3.
Tohoku University
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4.
Beijing Institute of Technology
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5.
Institute of Structure of Matter
Abstract
Modeling spin-wave (magnon) dynamics in novel materials is important to advance spintronics and spin-based quantum technologies. The interactions between magnons and lattice vibrations (phonons) limit the length scale for magnon transport. However, quantifying these interactions remains challenging. Here, we show many-body calculations of magnon-phonon (mag-ph) coupling based on the Bethe-Salpeter equation. We derive expressions for mag-ph coupling matrices and compute them in two-dimensional ferromagnets, focusing on hydrogenated graphene and monolayer CrI 3 . Our analysis shows that electron-phonon ( e − ph ) and mag-ph interactions differ significantly, where modes with weak e − ph coupling can exhibit strong mag-ph coupling (and vice versa), and reveals which phonon modes couple more strongly with magnons. In both materials studied here, the inelastic magnon relaxation times decrease abruptly above the threshold for emission of strongly coupled phonons, revealing a low-energy window where magnons are long lived. Averaging over this window, we compute the temperature-dependent magnon mean free path, a key figure of merit for spintronics, entirely from first principles. The theory and computational tools shown in this Letter enable studies of magnon interactions, scattering, and dynamics in generic materials, advancing the design of magnetic systems and magnon- and spin-based devices.
Copyright and License
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
Acknowledgement
K.B.L. and M.B. were supported by the National Science Foundation (NSF) under Grant No. OAC-2209262 for code and method development, and by the Air Force Office of Scientific Research (AFOSR) and Clarkson Aerospace Corp under Grants No. FA9550-21-1-0460 and No. FA9550-24-1-0004 for calculations on 2D materials. This work is supported by the European Union's Horizon Europe research and innovation program under the Marie Sklodowska-Curie Grant Agreement No. 101118915 (TIMES). This work is part of the project I +D +i PID2023-146181OB-I00 UTOPIA, funded by MCIN/AEI/10.13039/501100011033, Project No. PROMETEO/2021/082 (ENIGMA), and SEJIGENT/2021/034 (2D-MAGNONICS) funded by the Generalitat Valenciana. This study is also part of the Advanced Materials program (project SPINO2D), supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and by Generalitat Valenciana. A.M.-S. acknowledges the Ramon y Cajal program (Grant No. RYC2018-024024-I; MINECO, Spain). A.E.-K. acknowledges the Contrato Predoctoral Ref. PRE2021-097581. D.S. acknowledges funding from MaX “MAterials design at the eXascale” (Grant Agreement No. 101093374) cofunded by the European High Performance Computing joint Undertaking (JU) and participating countries, and from the Innovation Study Isolv-BSE that has received funding through the Inno4scale project, which is funded by the European High-Performance Computing Joint Undertaking (JU) (Grant Agreement No. 101118139).
Data Availability
Some of the data that support the findings of this article are openly available [67]. Code for computing magnon-phonon coupling matrices is not publicly available. The data are available from the authors upon reasonable request.
Files
489b-n5pd.pdf
Additional details
Related works
- References
- Journal Article: 10.1103/gbpw-zh1v (DOI)
Funding
- National Science Foundation
- OAC-2209262
- United States Air Force Office of Scientific Research
- European Research Council
- 101118915
- Ministerio de Ciencia, Innovación y Universidades
- PID2023-146181OB-I00
- Ministerio de Ciencia, Innovación y Universidades
- PROMETEO/2021/082
- Generalitat Valenciana
- SEJIGENT/2021/034
- Ministerio de Economía y Competitividad
- European High Performance Computing Joint Undertaking
Dates
- Available
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2025-11-07Published online
Caltech Custom Metadata
- Caltech groups
- Division of Engineering and Applied Science (EAS) , Division of Physics, Mathematics and Astronomy (PMA) , Physics Department
- Publication Status
- Published