Resonant excitation of spin waves in hybrid nanostructures via frequency combs

Abstract

Here we propose a new method of resonant optical excitation of spin waves in hybrid nanostructures via frequency comb. We consider a two-layer nanostructure consisting of an Au layer with a grating on the top and an yttrium iron garnet (YIG) thin film at the bottom. The plasmon evanescent fields induce time-independent magnetic polarization via the transverse magneto-optical Kerr effect (TMOKE) at the Au-YIG interface. Thus magnetic polarization in turn plays a role of a source for the excitation of the spin waves in YIG film. We show that by using the frequency comb as a source we can generate the magnetic polarization in resonance with the spin waves in YIG thus substantially increasing the magneto-optical response of the system. These results open new routes in the optical control of spintronics systems.