Zhao Wei, Yang Yuting, Tao Zhi, Hang Zhi Hong
School of Electronic and Information Engineering, Soochow University, Suzhou, 215006, China.
College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, 215006, China.
Sci Rep. 2018 Apr 20;8(1):6311. doi: 10.1038/s41598-018-24773-6.
Following the seminal work by Dubois et al. (Nat. Commun. 8, 14871 (2017)), we study a double-zero-index acoustic metamaterial with triangular lattice. By varying the height and diameter of air scatterers inside a parallel-plate acoustic waveguide, acoustic dispersion of the first-order waveguide mode can be manipulated and various interesting properties are explored. With accidental degeneracy of monopolar and dipolar modes, we numerically prove the double-zero-index properties of this novel acoustic metamaterial. Acoustic waveguides with tunable and asymmetric transmission are realized with this double-zero-index acoustic metamaterial embedded. Band inversion occurs if the bulk acoustic band diagram of this acoustic metamaterial is tuned. Deterministic interface states are found to exist on the interface between two acoustic metamaterials with inverted band diagrams.
继杜波依斯等人（《自然·通讯》8, 14871 (2017)）的开创性工作之后，我们研究了一种具有三角形晶格的双零折射率声学超材料。通过改变平行板声波导内空气散射体的高度和直径，可以操控一阶波导模式的声色散，并探索各种有趣的特性。由于单极模式和偶极模式的意外简并，我们通过数值方法证明了这种新型声学超材料的双零折射率特性。嵌入这种双零折射率声学超材料可实现具有可调谐和非对称传输的声波导。如果对这种声学超材料的体声波能带图进行调谐，就会出现能带反转。发现在具有反转能带图的两种声学超材料之间的界面上存在确定性界面态。
