Optical Excitation of Propagating Magnetostatic Waves in an Epitaxial Galfenol Film by Ultrafast Magnetic Anisotropy Change

Khokhlov, N. E.; Gerevenkov, P. I.; Shelukhin, L. A.; Azovtsev, A. V.; Pertsev, N. A.; Wang, M.; Rushforth, A. W.; Scherbakov, A. V.; Kalashnikova, A. M.

Abstract

© 2019 American Physical Society. Using a time-resolved optically pumped scanning-optical-microscopy technique, we demonstrate the laser-driven excitation and propagation of spin waves in a 20-nm film of a ferromagnetic metallic alloy Galfenol epitaxially grown on a GaAs substrate. In contrast to previous all-optical studies of spin waves, we employ laser-induced thermal changes of magnetocrystalline anisotropy as an excitation mechanism. A tightly focused 70-fs laser pulse excites packets of magnetostatic surface waves with an e-1-propagation length of 3.4μm, which is comparable with that of permalloy. As a result, laser-driven magnetostatic spin waves are clearly detectable at distances in excess of 10μm, which promotes epitaxial Galfenol films to the limited family of materials suitable for magnonic devices. A pronounced in-plane magnetocrystalline anisotropy of the Galfenol film offers an additional degree of freedom for manipulating the spin waves' parameters. Reorientation of an in-plane external magnetic field relative to the crystallographic axes of the sample tunes the frequency, amplitude, and propagation length of the excited waves.

Citation

Khokhlov, N. E., Gerevenkov, P. I., Shelukhin, L. A., Azovtsev, A. V., Pertsev, N. A., Wang, M., …Kalashnikova, A. M. (2019). Optical Excitation of Propagating Magnetostatic Waves in an Epitaxial Galfenol Film by Ultrafast Magnetic Anisotropy Change. Physical Review Applied, 12(4), Article 044044. https://doi.org/10.1103/PhysRevApplied.12.044044

• Journal Article Type: Article
• Acceptance Date: Sep 5, 2019
• Online Publication Date: Oct 18, 2019
• Publication Date: Oct 18, 2019
• Deposit Date: Oct 28, 2019
• Publicly Available Date: Oct 29, 2019
• Journal: Physical Review Applied
• Electronic ISSN: 2331-7019
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 4
• Article Number: 044044
• DOI: https://doi.org/10.1103/PhysRevApplied.12.044044
• Public URL: https://nottingham-repository.worktribe.com/output/2741980
• Publisher URL: https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.12.044044
• Additional Information: ©2019 American Physical Society