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Updated: Sep 5, 2025
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Published on: November 21, 2019
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Spin-phonon dispersion in magnetic materials
Mingqiang Gu1, Y H Bai2, G P Zhang3
1Department of Physics, Southern University of Science and Technology, Shenzhen 518055, People's Republic of China.
Summary
We introduce spin-phonon dispersion to map electron spin changes with lattice vibrations. This new concept reveals distinct spin enhancement and reduction branches, advancing our understanding of magnetic materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Microscopic spin-phonon coupling drives exotic properties in magnetic and non-magnetic materials.
- Traditional spin-phonon coupling constants inadequately describe complex electromagnetic behaviors.
Purpose of the Study:
- Introduce and define spin-phonon dispersion for comprehensive spin moment analysis.
- Map the entire spin change along phonon crystal momentum.
- Extend the Elliott-Yafet theory to magnetic materials.
Main Methods:
- Developed the concept of spin-phonon dispersion.
- Analyzed spin moment changes along phonon crystal momentum.
- Studied bcc Fe and hcp Co using spin force matrix analysis.
Main Results:
- Spin-phonon dispersion exhibits positive (enhancement) and negative (reduction) frequency branches.
- The spin force matrix in Fe and Co shows smaller diagonal elements compared to off-diagonal ones.
- This asymmetry results in distinctive spin-phonon dispersion patterns.
Conclusions:
- Spin-phonon dispersion provides a more complete picture of spin-lattice interactions than traditional methods.
- This framework enables the study of excited states in magnetic materials like CoF2 and NiO.
- The findings open new avenues for exploring THz-regime spin-lattice coupling.
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