Generation of spin waves via spin-phonon interaction in a buried dielectric thin film

International audienceIn this paper, we investigate the magnetic, optical, and lattice responses of a Pt/Cu/Bi 1 Y 2 Fe 5 O 12 /Gd 3 Ga 5 O 12 heterostructure to femtosecond laser excitation of the opaque Pt/Cu metallic bilayer. The electronic excitation generates coherent and incoherent phonons, which trigger high-frequency standing spin waves (SWs) in the dielectric Bi 1 Y 2 Fe 5 O 12 layer via a phonon-induced change of magnetic anisotropy. We find that the incoherent phonons (heat) can induce a fast (1000 ps) decrease of the magnetic order by different spin-phonon interaction scenarios. These results open perspectives for generating high-frequency SWs in buried magnetic garnets