Merging mechanical bound states in the continuum in high-aspect-ratio phononic crystal gratings

Hao Tong, Shengyan Liu, Kejie Fang

Research output: Contribution to journalArticlepeer-review

Abstract

Mechanical bound states in the continuum (BICs) present an alternative avenue for developing high-frequency, high-Q mechanical resonators, distinct from the conventional band structure engineering method. While symmetry-protected mechanical BICs have been realized in phononic crystals, the observation of accidental mechanical BICs—whose existence is independent of mode symmetry and tunable by structural parameters—has remained elusive. This challenge is primarily attributed to the additional radiation channel introduced by the longitudinal component of elastic waves. Here, we employ a coupled wave theory to predict and experimentally demonstrate mechanical accidental BICs within a high-aspect-ratio gallium arsenide phononic crystal grating. We observe the merging process of accidental BICs with symmetry-protected BICs, resulting in reduced acoustic radiation losses compared to isolated BICs. This finding opens up new possibilities for phonon trapping using BIC-based systems, with potential applications in sensing, transduction, and quantum measurements.

Original languageEnglish (US)
Article number197
JournalCommunications Physics
Volume7
Issue number1
DOIs
StatePublished - Dec 2024
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy

Fingerprint

Dive into the research topics of 'Merging mechanical bound states in the continuum in high-aspect-ratio phononic crystal gratings'. Together they form a unique fingerprint.

Cite this