Phonon transmission through a nonlocal metamaterial slab

• DOI: 10.1038/s42005-023-01184-2
• Publication Date: 2023-04-17T18:02:12Z
• Authors: Yi Chen; Ke Wang; Muamer Kadic; Sebastien Guenneau; Changguo Wang; Martin Wegener
• Keywords: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph]; 0301 basic medicine; Physics; QC1-999; ddc:530; Astrophysics; 530; [SPI.MAT]Engineering Sciences [physics]/Materials; 510; QB460-466; 03 medical and health sciences; [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics; info:eu-repo/classification/ddc/530

AbstractPrevious theory and experiment has shown that introducing strong (nonlocal) beyond-nearest-neighbor interactions in addition to (local) nearest-neighbor interactions into rationally designed periodic lattices called metamaterials can lead to unusual wave dispersion relations of the lowest band. For roton-like dispersions, this especially includes the possibility of multiple solutions for the wavenumber at a given frequency. Here, we study the one-dimensional frequency-dependent acoustical phonon transmission of a slab of such nonlocal metamaterial in a local surrounding. In addition to the usual Fabry-Perot resonances, we find a series of bound states in the continuum. In their vicinity, sharp Fano-type transmission resonances occur, with sharp zero-transmission minima next to sharp transmission maxima. Our theoretical discussion starts with a discrete mass-and-spring model. We compare these results with solutions of a generalized wave equation for heterogeneous nonlocal effective media. We validate our findings by numerical calculations on three-dimensional metamaterial microstructures for one-dimensional acoustical wave propagation.