Sound Waveguiding by Spinning: An Avenue toward Unidirectional Acoustic Spinning Fibers

Although optical fiber has revolutionized modern life, creating a corresponding fiber as a waveguide for airborne sound has proven difficult, due to the scarcity of high-index acoustic materials. In this study the authors utilize spinning of the air inside a metamaterial tube to create an acoustic fiber. Their simulations demonstrate nonreciprocal propagation resulting from the acoustic equivalent of the Zeeman effect, which leads to robust waveguiding in the proposed fiber. This contribution may open avenues for studying the physics of acoustic vortex beams and nonreciprocal phenomena.