2024-03-29T14:49:08Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/683752022-11-17T02:08:08Zhdl_2115_20045hdl_2115_139Time-domain imaging of gigahertz surface waves on an acoustic metamaterialOtsuka, Paul H.Mezil, SylvainMatsuda, OsamuTomoda, MotonobuMaznev, Alexei A.Gan, TianFang, NicholasBoechler, NicholasGusev, Vitalyi E.Wright, Oliver B.acousticgigahertzmetamaterialimagingsurface acoustic wavestime domainultrasonics420We extend time-domain imaging in acoustic metamaterials to gigahertz frequencies. Using a sample consisting of a regular array of similar to 1 mu mdiameter silica microspheres forming a two-dimensional triangular lattice on a substrate, we implement an ultrafast technique to probe surface acoustic wave propagation inside the metamaterial area and incident on the metamaterial from a region containing no microspheres, which reveals the acoustic metamaterial dispersion, the presence of band gaps and the acoustic transmission properties of the interface. A theoretical model of this locally resonant metamaterial based on normal and shear-rotational resonances of the spheres fits the data well. Using this model, we show analytically how the sphere elastic coupling parameters influence the gap widths.IOP PublishingJournal Articleapplication/pdfhttp://hdl.handle.net/2115/68375https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/68375/1/Otsuka_2018_New_J._Phys._20_013026.pdf1367-2630New Journal of Physics20130262018-01-22enginfo:doi/10.1088/1367-2630/aa9298http://creativecommons.org/licenses/by/3.0/publisher