Magnon-phonon relaxation in yttrium iron garnet from first principles

Abstract

We combine the theoretical method of calculating spin wave excitation with the finite-temperature modeling and calculate the magnon-phonon relaxation time in the technologically important material Yttrium iron garnet (YIG) from first principles. The finite lifetime of magnon excitation is found to arise from the fluctuation of the exchange interaction of magnetic atoms in YIG. At room temperature, the magnon spectra have significant broadening that is used to extract the magnon-phonon relaxation time quantitatively. The latter is a phenomenological parameter of great importance in YIG-based spintronics research. We find that the magnon-phonon relaxation time for the optical magnon is a constant while that for the acoustic magnon is proportional to $1/k^2$ in the long-wavelength regime.

References in corpus (8)

• Spin Seebeck insulator
• Strongly coupled magnons and cavity microwave photons
• Hybridizing ferromagnetic magnons and microwave photons in the quantum limit
• Spin Pumping in Electrodynamically Coupled Magnon-Photon Systems
• Identification of the dominant precession damping mechanism in Fe, Co, and Ni by first-principles calculations
• Thermal spin dynamics of yttrium iron garnet
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• Direct Method for Calculating Temperature-Dependent Transport Properties

Cited by in corpus (3)

• Magnon-phonon interactions in magnetic insulators
• Strain-Tunable Magnetic Compensation Temperature of Epitaxial Tb${}_3$Fe${}_5$O${}_{12}$ Thin Films
• Ultrafast Optomagnonics in Ferrimagnetic Multi-Sublattice Garnets