Wang Ji-Qian, Zhang Zi-Dong, Yu Si-Yuan, Ge Hao, Liu Kang-Fu, Wu Tao, Sun Xiao-Chen, Liu Le, Chen Hua-Yang, He Cheng, Lu Ming-Hui, Chen Yan-Feng
National Laboratory of Solid State Microstructures & College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China.
Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
Nat Commun. 2022 Mar 14;13(1):1324. doi: 10.1038/s41467-022-29019-8.
Stable and efficient guided waves are essential for information transmission and processing. Recently, topological valley-contrasting materials in condensed matter systems have been revealed as promising infrastructures for guiding classical waves, for they can provide broadband, non-dispersive and reflection-free electromagnetic/mechanical wave transport with a high degree of freedom. In this work, by designing and manufacturing miniaturized phononic crystals on a semi-infinite substrate, we experimentally realized a valley-locked edge transport for surface acoustic waves (SAWs). Critically, original one-dimensional edge transports could be extended to quasi-two-dimensional ones by doping SAW Dirac "semimetal" layers at the boundaries. We demonstrate that SAWs in the extended topological valley-locked edges are robust against bending and wavelength-scaled defects. Also, this mechanism is configurable and robust depending on the doping, offering various on-chip acoustic manipulation, e.g., SAW routing, focusing, splitting, and converging, all flexible and high-flow. This work may promote future hybrid phononic circuits for acoustic information processing, sensing, and manipulation.
稳定且高效的导波对于信息传输和处理至关重要。最近，凝聚态物质系统中的拓扑谷对比材料已被证明是引导经典波的有前途的基础结构，因为它们可以提供具有高度自由度的宽带、非色散和无反射的电磁/机械波传输。在这项工作中，通过在半无限基板上设计和制造小型化声子晶体，我们通过实验实现了表面声波（SAW）的谷锁定边缘传输。至关重要的是，通过在边界处掺杂SAW狄拉克“半金属”层，可以将原始的一维边缘传输扩展为准二维传输。我们证明，扩展的拓扑谷锁定边缘中的SAW对弯曲和波长尺度的缺陷具有鲁棒性。此外，根据掺杂情况，这种机制是可配置且稳健的，可提供各种片上声学操纵，例如SAW路由、聚焦、分裂和会聚，所有这些都灵活且高效。这项工作可能会推动未来用于声学信息处理、传感和操纵的混合声子电路的发展。
