Influence of three-magnon decays on electromotive force generation by magnetostatic surface waves in integral YIG - Pt structures

The purpose of this work is to find out the influence of three-magnon decay processes on the electromotive force (EMF (U)) generated by propagating magnetostatic surface waves (MSSW) with the help of the inverse spin Hall effect in the "yttrium-iron garnet (YIG) - platinum (Pt)" structure. Methods. The experiments were carried out using the delay line structures based on YIG films with the thickness of 8.8 and 14.6 $\mu$m, on the surface of which antennas were formed for MSSWs excitation and reception and a Pt film between antennas. Results. It was shown that the three-magnon parametric instability can significantly change the character of EMF dependences on frequency and on power of MSSW that resulted both from the effect of power limitation and from the participation of parametric spin waves (PSW) and secondary spin waves (SSW) in the processes of electron-magnon scattering on the YIG/Pt border. Conclusion. It was demonstrated that the effect of amplification of EMF generation at the frequencies that are close to the long-wavelength border of the MSSW spectrum is related with the PSW and SSW population of the region of anisotropic dipole-exchange spin waves spectrum, which is characterized by the presence of singularities in the magnon density of states (Van Hove singularities).