One-Way Sound Transport

Topological phases are defined by geometric constraints, which makes them especially robust against environmental influences. Although typically an electronic phenomenon, topological phases can also occur in acoustic systems. Researchers have now assembled an array of air channels to create the acoustic version of a topological phase known as a Chern insulator. Their acoustic device limits the propagation of sound waves to a single direction, which could benefit medical ultrasound and the control of environmental noise.