基于合成维度空间中深亚波长拓扑角态的声彩虹捕获  

Synthesizing topological acoustic rainbow trapping at deep-subwavelength corners

作　　者：廖丹薇 刘翊贤 张志旺 程营 刘晓峻 Johan Christensen Danwei Liao;Yixian Liu;Zhiwang Zhang;Ying Cheng;Xiaojun Liu;Johan Christensen(Department of Physics,MOE Key Laboratory of Modern Acoustics,Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China;State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;College of Aerospace Engineering,Chongqing University,Chongqing 400044,China;IMDEA Materials Institute,Madrid 28906,Spain)

机构地区：[1]Department of Physics,MOE Key Laboratory of Modern Acoustics,Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China [2]State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China [3]College of Aerospace Engineering,Chongqing University,Chongqing 400044,China [4]IMDEA Materials Institute,Madrid 28906,Spain

出　　处：《Science Bulletin》2023年第16期1744-1747,M0003,共5页科学通报（英文版）

基　　金：supported by the National Key R&D Program of China (2022YFA1404400 and 2022YFA1404500);the National Natural Science Foundation of China (12074183, 11834008, 12104226, 12225408, and 12227809);the Fundamental Research Funds for the Central Universities (020414380181 and 020414380211);the support from the Funds for Zijin Scholars of Nanjing University;he support from the Spanish Ministry of Science and Innovation through a Consolidación Investigadora grant (CNS2022-135706)。

摘　　要：近年来,拓扑声学相关研究发展迅猛,其理论最初源于凝聚态物理中所发现的拓扑特性.其中,声学高阶拓扑绝缘体支持能量高度局域在拐角处的低维拓扑角态,且本征频率简并.然而,如何打破拓扑角态的多重简并,实现可调控的频率分布并设计新型声学多功能拓扑器件,是亟待解决的关键问题.在该研究中,通过对二维声子晶体中的单元施加平移形变,与真实空间自由度相结合构建四维合成空间.研究发现,随着平移形变自由度的调制,Zak相位连续变化,而合成空间的非零拓扑不变量确保了系统的非平庸拓扑特性,拓扑角态的频率简并被打破.基于此结论,进一步设计了基于合成维度的声学高阶拓扑绝缘体阵列,以实现局域在深亚波长拐角上的双通道声彩虹捕获.实验结果表明,不同通道上声彩虹拓扑角态的本征频率增加方向相反,在空间选择性能量捕获等领域具有潜在的应用前景.Topological boundary states,the smoking gun of topological insulators(TIs),have been widely investigated in a variety of settings[1,2].Among the youngest members of this seemingly growing family,we have higher-order topological insulators(HOTIs)whose lower-dimensional topological corner states violate the conventional bulk-boundary correspondence[3].Benefiting from cunningly contrived designs and the aid of 3D printing,sonic crystals(SCs)have served as ideal platforms to study topological properties in an acoustic context.Among them,prototypical models to achieve two-dimensional(2D)acoustic HOTIs include Su–Schrief fer–Heeger(SSH)model and quadrupole TI[4],where the degenerate corner states are observed within a single band gap and are typically characterized by a binary topological invariant(zero for trivial and one for nontrivial)。

关 键 词：拓扑绝缘体 本征频率 拓扑特性 凝聚态物理 能量高度 空间选择性 空间自由度 能量捕获 

分 类 号：O469[理学—凝聚态物理]