Subwavelength Acoustic Valley-Hall Topological Insulators Using Soda Cans Honeycomb Lattices
(a) Dispersion relation of the ribbon-shaped PnC near the frequency of the first-order resonance with different interfaces (I-II and II-I) comprised of 6 cells on either side. Gray circles represent bulk states and red/blue dots represent the edge states along different interfaces. Distributions of the absolute pressure fields at for the interface (b) I-II and (c) II-I, respectively, which are labeled in (a). (d)-(f) Same as (a)-(c), but induced by the second-order resonance.