GHz Love-mode TF-SAW phononic crystals based on LiNbO3-on-SiC substrate

We demonstrate thin-film surface acoustic wave (TF-SAW) phononic crystals (PnCs) by etching a square lattice array of micropores into a 300 nm LiNbO3-on-SiC substrate, harnessing the remarkable properties of Love modes. Our design enables tailorable bandgaps from 2.026 to 2.347 GHz (approximately 15% bandwidth) along Γ-X, extending up to 3.167 GHz along Γ-M, with experimental measurements confirming Love mode attenuation up to 40 dB. By precisely engineering the micropore geometry and layer configuration, we effectively tune both the position and width of the bandgaps. These TF-SAW PnCs offer powerful acoustic wave manipulation capabilities and scalability, opening horizons for high-throughput communication, sensing, microfluidics, and emerging quantum acoustics technologies.