Hypersonic acoustic wave control via hyperuniform phononic nanostructures

TL;DR

This paper demonstrates the use of hyperuniform phononic nanostructures to control hypersonic surface acoustic waves, achieving bandgap formation and waveguiding, which enhances phononic device capabilities beyond traditional periodic structures.

Contribution

The study introduces hyperuniform arrangements of nanopillars as a new method for suppressing and guiding hypersonic waves, surpassing limitations of conventional phononic crystals.

Findings

Hyperuniform structures reduce acoustic transmission and create bandgap-like regions.

Waveguides within hyperuniform patterns enable high transmission at specific frequencies.

Experimental and simulation results confirm effective wave control using 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 the control of surface acoustic waves using a hyperuniform arrangement of gold nanopillars on a lithium niobate layer. The hyperuniform structure exhibits characteristics of both random and ordered systems, leading to an overall reduction in acoustic transmission and the formation of bandgap-like regions where phonon propagation is strongly suppressed. We further demonstrate effective waveguiding by incorporating linear and S-shaped waveguides into the hyperuniform pattern. Both simulations and experiments confirm high transmission through the waveguides at frequencies within the bandgaps, demonstrating the flexibility of hyperuniform structures to support waveguides of complex shapes. These findings provide a novel approach to overcoming the limitations of traditional phononic crystals and advancing acoustic technologies in applications such as mechanical quantum computing and smartphone filters.