SPIN-WAVE EXPERIMENTS: PARAMETRIC EXCITATION OF ACOUSTIC WAVES AND MODE-LOCKING OF SPIN WAVES

Abstract

In a spin-wave instability experiment, a YIG disk was bonded onto a quartz rod with a transducer attached to it, and was placed in a microwave cavity in a parallel-pumping arrangement. For microwave power above the threshold for spin-wave instability, parametric generation of acoustic waves was observed. The generation was evidenced by the simultaneous appearance of a low-frequency oscillation in the reflected microwave power and at the transducer. In a subsequent experiment, a low-frequency acoustic wave was sent into YIG through the transducer. A great enhancement of the oscillation in the reflected microwave power was observed. The enhancement was due to phase-locking of spin-wave modes.