Fig. 4: Control the transmission of CABSs by adjusting the boundary modifications.
From: Observation of boundary induced chiral anomaly bulk states and their transport properties
a–c Simulated acoustic pressure field distributions at 15.5 kHz for a point source in three different configurations of the 60-degree-bend PCs. The PC in a is composed of two waveguides with the same band dispersion (with periodic boundary conditions in the \(x\)- and \(x\)′-directions). The PC in b is composed of two waveguides with inverted K and K′ valleys in the band dispersion. The width of the waveguide in domain 4 is smaller than that of domain 1 by one layer. The PC in c is composed of two waveguides with the same band dispersion, featuring some boundary modifications at the coupling position (compared with a, a rigid boundary is added at 60 degrees to the \(x\) axis at the position \(2a\) away from the bottom right corner along the -\(x\) axis). The modification of b, c is shown in Fig. S5. The inset pictures in b, c are the experimental Fourier spectra of the acoustic field in the corresponding magenta dashed rectangles. d–f Fourier spectra in momentum space for domains 1, 3, and 4. The right panels display the corresponding projected band structures along the \(x\), \(x\)′ and \(x\)′ directions.
