Fig. 4. Experimental results for controlling the edge mode of surface acoustic waves.
Configurations of valley phononic crystals (PCs) for transporting surface acoustic waves (SAWs) along a straight and f Z-shaped interfaces. The blue and brown circles represent shallow and deep cavities. Experimental pressure fields of SAWs propagating along the b–d straight and g–i Z-shaped paths at 4.55, 4.75, and 4.95 kHz, when the depth changes Hδ are 0, −1 and −2 mm, respectively. The acquired pressure fields confirm that the valley Hall edge mode of SAWs can be generated in our valley PCs. Experimental transmission spectra of SAWs along the e straight and j Z-shaped paths. As the depth change Hδ decreases, the edge mode’s frequency increases.