Gallium nitride phononic integrated circuits platform for GHz frequency acoustic wave devices

Strong transverse confinement of high-frequency sound and low-loss routing in on-chip waveguides will bring new degrees freedom to manipulate GHz frequency acoustic waves, analogous the change brought forth by silicon integrated photonics manipulation light on a chip. Here, we demonstrate that high (>3 GHz) can be efficiently guided ?m-scale gallium nitride (GaN) ring resonators exploiting strong velocity contrast available GaN carbide (SiC) platform. Given established use devices RF amplifiers, our work opens up possibility building with tight integration between active passive components same die.