Reconfigurable Floquet elastodynamic topological insulator based on synthetic angular momentum bias
Reconfigurable Floquet elastodynamic topological insulator based on synthetic angular momentum bias
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DOI：
10.1126/sciadv.aba8656
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发表时间：
2020-07-01
期刊：
影响因子：
13.6
通讯作者：
Alu, Andrea
中科院分区：
文献类型：
--
作者：
Darabi, Amir;Ni, Xiang;Alu, Andrea
起源于凝聚态物理中量子霍尔效应（QHE）的发现，拓扑序对于经典波动现象也越来越受到关注。拓扑保护可实现高效、稳健的信号传输；特别是，机械拓扑绝缘体（TI）易于制造，即使存在尖锐边缘、缺陷或无序，也能以最小的耗散表现出界面波传输。在这里，我们报告了声子晶体 Floquet TI (FTI) 的实验演示。圆形压电盘的六边形阵列粘合到 PLA 基板上，通过负电容分流，并由外部集成电路操纵，提供了所需的时空调制方案，以打破时间反转对称性并赋予合成角动量偏置，从而在晶格边缘上产生强大的拓扑保护。我们提出的可重构 FTI 可能会应用于稳健的声学发射器和机械逻辑电路，在恶劣的工作条件下比电子等效电路具有明显的优势。
Originating with the discovery of the quantum Hall effect (QHE) in condensed matter physics, topological order has been receiving increased attention also for classical wave phenomena. Topological protection enables efficient and robust signal transport; mechanical topological insulators (TIs), in particular, are easy to fabricate and exhibit interfacial wave transport with minimal dissipation, even in the presence of sharp edges, defects, or disorder. Here, we report the experimental demonstration of a phononic crystal Floquet TI (FTI). Hexagonal arrays of circular piezoelectric disks bonded to a PLA substrate, shunted through negative electrical capacitance, and manipulated by external integrated circuits, provide the required spatiotemporal modulation scheme to break time-reversal symmetry and impart a synthetic angular momentum bias that can induce strong topological protection on the lattice edges. Our proposed reconfigurable FTI may find applications for robust acoustic emitters and mechanical logic circuits, with distinct advantages over electronic equivalents in harsh operating conditions.