This paper experimentally demonstrates the control of sound waves using engineered acoustic systems where synthetic pseudo-spin emerges due to the evanescent nature of the field or lattice symmetry. Evanescent sound waves in perforated films exhibit transverse angular momentum enabling directional excitation. Lattice symmetries in an acoustic kagome lattice enable synthetic transverse pseudo-spin, controlling mode propagation in the bulk and along edges. This work opens new avenues for controlling acoustic wave radiation and propagation, leading to novel acoustic device designs.

Matthew Weiner, Xiang Ni, Andrea Alù, Alexander B. Khanikaev