Hybridized Propagation of Spin Waves and Surface Acoustic Waves in a Multiferroic-Ferromagnetic Heterostructure

Coherent coupling in magnon-based hybrid systems has many potential applications in quantum information processing. Magnons can propagate in magnetically ordered materials without any motion of electrons, offering a unique method to build low-power-consumption devices and information channels free of heat dissipation. In this paper, we demonstrate the coherent propagation of hybridized modes between spin waves and Love surface acoustic waves in a multiferroic BiFeO3 and ferromagnetic La0.67Sr0.33MnO3-based heterostructure. The magnetoelastic coupling enables a giant enhancement of the strength of the hybridized mode by a factor of 26 compared to that of the pure spin waves. A short wavelength down to 250 nm is demonstrated for the hybridized mode, which is desirable for nanoscale acoustomagnonic applications. Our combined experimental and theoretical analyses represent a step towards the coherent control in hybrid magnonics, which may inspire the study of magnon-phonon hybrid systems for coherent information processing and manipulation.