Band Gap Optimization for GHz Elastic Waves in Gold Phononic Crystals

Abstract

Abstract Elastic waves at GHz range have many interesting applications, such as microwave generation, hybrid-information processing and quantum routing. The phononic crystals (PhnCs) can help manipulate the propagation of elastic waves, due to their bandgap effect. In order to produce relatively broad phononic bandgap in the GHz range, here three types of PhnCs in gold are investigated. Phononic bandgaps are optimized in terms of tuning the shape and size of air holes. Results as provided by the finite element method show that the maximum of the gap ratio ~0.991 appears in the cross-shaped PhnCs. The proposed gold-based PhnCs may be useful for building optomechanical platform which can realize strong surface-plasmon-mechanical coupling.