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

In this paper, we investigate the magnetic, optical, and lattice responses of a Pt/Cu/Bi1Y2Fe5O12/Gd3Ga5O12 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 Bi1Y2Fe5O12 layer via a phonon-induced change of magnetic anisotropy. We find that the incoherent phonons (heat) can induce a fast (<1ps) and slow (>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.

Automated summary

This paper investigates the magnetic, optical, and lattice responses of a Pt/Cu/Bi1Y2Fe5O12/Gd3Ga5O12 heterostructure to femtosecond laser excitation, revealing the generation of high-frequency standing spin waves in the dielectric Bi1Y2Fe5O12 layer through phonon-induced change of magnetic anisotropy. It is found that incoherent phonons can lead to both fast and slow decreases of magnetic order through different spin-phonon interaction scenarios.