Bragg Resonances in a Yttrium Iron Garnet–Platinum–Yttrium Iron Garnet Layered Structure

A theoretical study is performed of the interaction between spin current in a strongly spin-orbit-coupled platinum (Pt) conductor and a spin wave in ferromagnetic layers of yttrium iron garnet (YIG) with periodic modulation of their thickness under conditions of Bragg resonances and interlayer bond. It is shown that the conditions for two Bragg resonances in the first Brillouin zone in the spin wave spectrum are satisfied in the YIG/Pt/YIG sandwich structure. The spin current in Pt allows the frequency tuning of resonances and control over the depth of the spin wave band gap corresponding to the resonance conditions.