Topologically protected one-way acoustic splitter using antichiral edge states

The unidirectional manipulation of sound propagation is crucial for developing nonreciprocal devices, as it efficiently enhances application performance by preventing interference. In this work, we propose a design for a topologically protected nonreciprocal splitter for acoustic waves, utilizing the anomalous feature of dual edge-localized, unidirectional parallel transmission. Our design integrates two opposite modified-Haldane-type acoustic crystals, whose unit cell consists of two ring resonators with staggered airflow circulation, to orchestrate the splitting mechanism. We show distinctive phenomena, including tilted edge bands and copropagating one-way edge-localized acoustic wave propagation via simulations. The nonreciprocal splitting behavior is further demonstrated by the bidirectional propagation along edges of the input acoustic wave at the interface. Additionally, we leverage its functionality to independently transmit two channels of different acoustic information. Our findings not only provide a viable scheme of experimental implementation, but also open avenues for expanding the application of topologically protected antichiral edge states in acoustic communication.