Fig. 1: Acoustic parametric pumping of spin waves.
From: Sustained amplification of coherent spin waves by parametric pumping with surface acoustic waves
a Illustration of the parametric interaction between a spin wave and a SAW pump. b Calculated dispersion curves for forward volume spin waves in a 1 µm-thick YIG film and surface acoustic waves in a layered medium of ZnO (425 nm) on YIG. In the parametric pumping interaction, a pump phonon splits into two magnons of half the pump frequency, and the wave vectors must satisfy the conservation relation in Eq. (2). c Experimental configuration. Spin waves are excited and detected in the YIG film by inductive transducers. The surface acoustic wave pump is generated using an interdigitated transducer (IDT) on piezoelectric ZnO. The bias magnetic field is oriented perpendicular to the film plane. d Optical micrograph of a fabricated device showing the layout of the transducers. (The L-shaped features near the spin wave transducers are inadvertent artifacts of the lithography process and do not impact the experiments).
