The Interaction between Surface Acoustic Waves and Spin Waves: The Role of Anisotropy and Spatial Profiles of the Modes

Abstract

The interaction between different types of wave excitation in hybrid systems is usually anisotropic. Magnetoelastic coupling between surface acoustic waves and spin waves strongly depends on the direction of the external magnetic field. However, in the present study we observe that even if the orientation of the field is supportive for the coupling, the magnetoelastic interaction can be significantly reduced for surface acoustic waves with a particular profile in the direction normal to the surface at distances much smaller than the wavelength. We use Brillouin light scattering for the investigation of thermally excited phonons and magnons in a magnetostrictive CoFeB/Au multilayer deposited on a Si substrate. The experimental data are interpreted on the basis of a linearized model of interaction between surface acoustic waves and spin waves.

Spin Wave Electromagnetic Nano‐Antenna Enabled by Tripartite Phonon‐Magnon‐Photon Coupling

“…[ 9 , 10 ] Other studies of coupling between spin waves and SAW have also been reported. [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ] Here, we have harnessed this interaction to implement a novel antenna whose gain and radiation efficiency exceed the theoretical limits by two orders of magnitude or more.…”

Impact of Spin Wave Dispersion on Surface Acoustic Wave Velocity

“…Therefore the in-plane anisotropy of SWs dispersion has to be taken into account for the design of magnonic devices where SAW are exploited to control or generate SWs. Interestingly, some recent articles put into evidence the important role played by a nonzero wavevector [12][13][14].…”

“…In particular, Babu et al studied the SAW-SW coupling by Brillouin Light Scattering (BLS) in a wide kvalues range [14]. They showed that in order to obtain an appreciable coupling between SWs and SAWs, the SAW profile within the magnetostrictive layer is also of importance, [14] in addition to the anisotropy of the magnetoelastic interaction with respect to the orientation of the magnetic field [10].…”

Magnetization dynamics affected by phonon pumping

“…The study of magnon-phonon interactions in highquality magnets has a long history [14][15][16][17][18][19][20][21]. The arrival of crystal growth techniques, strongly improved microwave technology, and discovery of new phenomena such as the spin Seebeck effect, led to a revival of the subject in the past few years, with emphasis on ultrathin films and heterostructures [4,6,[22][23][24][25][26][27][28][29][30].…”