Topological pseudospin switcher: Mechanism and acoustic realization
摘要
The control of the pseudospin of sound wave has attracted increasing attention in recent years. Utilizing the finite-size effect of topological acoustics, we successfully construct an H-shaped acoustic topological pseudospin switcher that sound wave energy can be easily switched through different passages. The interesting phenomenon of pseudospin flipping is numerically and experimentally demonstrated. A quantitative interference theory is proposed that the constructive and destructive interference of pseudospin states leads to pseudospin flipping and preserving in multiple frequencies. We verify the key parameters of the design, including the length of the passage and its interface state dispersion, and the theory can be extended to other topology acoustics and photonics systems. Moreover, the tunable topological sonic crystal we use provides adjustable convenience to pseudospin switcher design. The pseudospin switching behavior offers an efficient method to control the acoustic topological edge state transport, which has great potential in versatile applications, such as integrated acoustics, acoustic security, and information processing.