Phononic Band Structure Engineering for High- Q Gigahertz Surface Acoustic Wave Resonators on Lithium Niobate

Abstract

Surface acoustic waves (SAWs) serving as universal interfaces are intriguing for hybrid systems with classical and quantum components. This study demonstrates a method for designing a high-quality SAW resonator using phononic band structure engineering. The SAW resonator presents a quality factor $Q$ > 104 at gigahertz frequencies, yielding a figure of merit (the product of frequency and $Q$) of 10${}^{13}$ at room temperature. Improvements in $Q$ at cryogenic temperatures are also observed. The presented methodology paves the way for hybrid classical-quantum phonon networks.