Hypersonic acoustic wave control via stealthy hyperuniform phononic nanostructures.

Abstract

Controlling hypersonic surface acoustic waves is crucial for advanced phononic devices such as high-frequency filters, sensors, and quantum computing components. While periodic phononic crystals enable precise bandgap engineering, their ability to suppress acoustic waves is limited to specific frequency ranges. Here, we experimentally demonstrate surface acoustic wave control using a hyperuniform arrangement of gold nanopillars on a lithium niobate layer. The hyperuniform structure, exhibiting characteristics of both random and ordered systems, leads to broad-range acoustic transmission reduction and bandgap-like regions of particularly strong suppression. By integrating linear and S-shaped waveguides into the hyperuniform pattern, we achieve efficient waveguiding at frequencies within these bandgaps. Both simulations and experiments confirm high transmission through the waveguides, demonstrating the flexibility of hyperuniform structures to support complex waveguide shapes. These findings provide an alternative approach to overcome limitations of traditional phononic crystals and advance acoustic technologies such as mechanical quantum computing and smartphone filters.