Fig. 3. Experimental validation of edge states and bulk-edge correspondence for acoustic satellite Dirac cones.

a Measured acoustic pressure field of the PC with a source placed at the middle of the upper boundary. b Measured (colormaps) and simulated (gray dots) acoustic edge state dispersions. c Schematic of the first BZ. The vertical dashed lines in (b) mark the projections of Dirac points, as illustrated in (c), while the vertical solid lines in orange, red, and blue highlight $k_x=0$, $0.25$, and $0.36$, respectively. d, e Simulated acoustic eigenfields at the upper boundary for $k_x=0.25$ and $0.36$, respectively. f–h Acoustic bulk dispersions along the colored vertical lines in (c). i–k Measured (dots) and simulated (lines) pseudospin trajectories of the first bands in (f-h).