Chen Yafeng, Fan Lei, Zhu Jie, Su Zhongqing
Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, 999077, China.
Institute of Acoustics, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China.
Adv Sci (Weinh). 2025 Jan;12(4):e2411398. doi: 10.1002/advs.202411398. Epub 2024 Dec 4.
Second-order elastic topological insulators (SETIs) with tightly localized corner states present a promising avenue for manipulating elastic waves in lower dimensions. However, existing SETIs typically support corner states of only a single mode, either out-of-plane or in-plane. In this work, an on-chip SETI that simultaneously hosts both high-frequency out-of-plane and in-plane corner states at ≈0.2 MHz is introduced. The presence of these corner states is experimentally validated, and their selective excitation by tuning the excitation frequency is demonstrated. This capability to demultiplex out-of-plane and in-plane corner states positions the SETI as a potential platform for developing multifunctional elastic devices and enhancing the communication capacities of elastic waves. Furthermore, due to its structural simplicity, the SETI can be readily scaled and integrated into on-chip elastic circuits, making it suitable for applications in micro-electromechanical systems.
具有紧密局域化角态的二阶弹性拓扑绝缘体（SETIs）为在低维空间中操控弹性波提供了一条很有前景的途径。然而，现有的SETIs通常仅支持单模角态，要么是面外模式，要么是面内模式。在这项工作中，引入了一种片上SETI，它能在≈0.2 MHz频率下同时承载高频面外和面内角态。通过实验验证了这些角态的存在，并展示了通过调谐激发频率对它们进行选择性激发的方法。这种对面外和面内角态进行解复用的能力，使SETI成为开发多功能弹性器件和增强弹性波通信能力的潜在平台。此外，由于其结构简单，SETI可以很容易地进行缩放并集成到片上弹性电路中，适用于微机电系统中的应用。
