- Letter
When phononic crystals fail: Spatial and spectral limits of phonon interference
Phys. Rev. Applied 24, L061001 – Published 2 December, 2025
DOI: https://doi.org/10.1103/4h35-f4kz
Abstract
This paper is a contribution to the Physical Review Applied collection titled Phononics and Metamaterials.
Phononic crystals are artificial periodic structures that leverage phonon-wave interference to control mechanical vibrations. Their practical implementations range from evenly planted trees to periodic nanostructures covering mechanical vibrations from seismic waves to sound and heat. However, the spatial and spectral limits at which phonon interference disappears are unknown. Here, we report on experimental observations of a gradual breakdown of phonon interference in two-dimensional nanoscale phononic crystals. Measured phonon dispersion relations reveal the critical dimensions and frequencies at which phonons no longer sense the in-plane periodicity of the crystal and enter an intermediate state dominated by out-of-plane interference before ceasing to interfere altogether. These findings refine the current understanding of nanoscale phonon interference and might be relevant for phononic crystal applications in microelectronics and acoustic quantum computing.
Physics Subject Headings (PhySH)
Collections
This article appears in the following collection:
Phononics and Metamaterials
Physical Review Applied is pleased to present a Collection on Phononics and Metamaterials, in which diverse developments in research on sound waves are gathered to offer a comprehensive view of both the state of the art and the challenges ahead. The Collection is dedicated to the memory of Dr. Sarah Benchabane (1980–2024), honoring her outstanding contributions to phononics and wave physics. Contributions to this Collection will be published beginning in 2025 and continuing into 2026. This Collection is being curated by Guest Editors Muamer Kadic, Daniel Torrent, and Abdelkrim Khelif.
