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arXiv · 2410.16209

Bound States-to-Bands in the Continuum in Cylindrical Granular Crystals

Yeongtae Jang·Seokwoo Kim·Dongwoo Lee·Eunho Kim·Junsuk Rrho
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Abstract

We theoretically investigate and experimentally demonstrate that genuine bound states in the continuum (BICs) -- polarization-protected BICs -- can be completely localized within finite-size solid resonators. This bound mode is realized in a highly tunable mechanical system made of cylindrical granular crystals, where tunning the contact boundaries enables the in situ transition from the BICs to quasi-BICs in a controllable manner. Since a single-particle resonator can support BICs itself, these bound states can extend to form bound bands within periodic structures composed of such resonators. We experimentally demonstrate the emergence of a quasi-bound (flat) band in a finite chain with broken resonator symmetry, using a laser Doppler vibrometer. Remarkably, we show that all cylindrical resonators within the entire chain exhibit high-Q and dispersionless resonance.

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Yeongtae Jang, Seokwoo Kim, Dongwoo Lee, Eunho Kim, Junsuk Rrho. 2024-10-21. Bound States-to-Bands in the Continuum in Cylindrical Granular Crystals. https://arxiv.org/abs/2410.16209

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