Theory of polarization-dependent phonon pumping in ferromagnetic/non-magnetic bilayers
Cherkasskii M, Engelhardt F, Müller M, Weber J, Althammer M, Goennenwein ST, Huebl H, Viola Kusminskiy S (2025)
Publication Type: Journal article
Publication year: 2025
Journal
Book Volume: 138
Article Number: 043906
Journal Issue: 4
DOI: 10.1063/5.0273075
Abstract
We develop a theoretical model for polarization-selective phonon pumping induced by magnon-phonon coupling in a ferromagnetic/non-magnetic acoustic bilayer structure, focusing on the effects arising from a misalignment between the magnetic and crystallographic symmetry axes. Our model considers the coupled equations of motion describing uniform magnetization dynamics (the Kittel mode) and elastic waves in both layers, incorporating phonon pumping and boundary conditions at the interface. We show that even small misalignments lift the degeneracy of transverse shear elastic modes, resulting in phononic birefringence characterized by distinct propagation velocities for linearly polarized modes. Furthermore, our analysis reveals that magnon-phonon hybridization gives magnetic-field-dependent properties to otherwise non-magnetic phonons. We show that the polarization transfer between linearly polarized phonons and the circularly polarized Kittel mode can be tuned with an external magnetic field. Our theoretical results quantitatively reproduce recent experimental findings [M. Müller, Phys. Rev. B 109, 024430 (2024)].
Involved external institutions
Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen
Germany (DE)
Walther-Meißner-Institut für Tieftemperaturforschung
Germany (DE)
Universität Konstanz
Germany (DE)
Germany (DE)
Walther-Meißner-Institut für Tieftemperaturforschung
Germany (DE)
Universität Konstanz
Germany (DE)
How to cite
APA:
Cherkasskii, M., Engelhardt, F., Müller, M., Weber, J., Althammer, M., Goennenwein, S.T.,... Viola Kusminskiy, S. (2025). Theory of polarization-dependent phonon pumping in ferromagnetic/non-magnetic bilayers. Journal of Applied Physics, 138(4). https://doi.org/10.1063/5.0273075
MLA:
Cherkasskii, M., et al. "Theory of polarization-dependent phonon pumping in ferromagnetic/non-magnetic bilayers." Journal of Applied Physics 138.4 (2025).
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