Spin-wave instability threshold in single-crystal yttrium iron garnet for oblique pumping

Abstract

The spin-wave instability threshold hcrit for oblique pumping in high-quality single-crystal yttrium iron garnet (YIG) at room temperature and 9.317 GHz, has been examined. The experimental dependence of hcrit on the pump angle indicates that the microwave field components parallel and perpendicular to the dc field operate independently in exciting spin-wave instability. Theoretical fits to the data, based on this result, indicate that the spin-wave linewidth is strongly wave vector dependent and that the wave vector dependence varies with the pump angle.