基于万尼尔构型观测声学拓扑角模式反常  

Observations of acoustic Wannier configurations revealing topological corner anomaly

作　　者：张鹏 贾晗 陆久阳 杨星航 王苏豪 杨玉真 刘正猷 杨军 Peng Zhang;Han Jia;Jiuyang Lu;Xinghang Yang;Suhao Wang;Yuzhen Yang;Zhengyou Liu;Jun Yang(Key Laboratory of Noise and Vibration Research,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;School of Physics and Optoelectronics,South China University of Technology,Guangzhou 510641,China;Key Laboratory of Artificial Micro-and Nano-Structures of Ministry of Education and School of Physics and Technology,Wuhan University,Wuhan 430072,China;Institute for Advanced Studies,Wuhan University,Wuhan 430072,China)

机构地区：[1]Key Laboratory of Noise and Vibration Research,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China [4]School of Physics and Optoelectronics,South China University of Technology,Guangzhou 510641,China [5]Key Laboratory of Artificial Micro-and Nano-Structures of Ministry of Education and School of Physics and Technology,Wuhan University,Wuhan 430072,China [6]Institute for Advanced Studies,Wuhan University,Wuhan 430072,China

出　　处：《Science Bulletin》2023年第7期679-683,共5页科学通报（英文版）

基　　金：This work was supported by the Key-Area Research and Development Program of Guangdong Province(2020B010190002);the National Natural Science Foundation of China(11890701,11874383,12104480,11974005,and 12222405);the National Key R&D Program of China(2018YFA0305800);the IACAS Frontier Exploration Project(QYTS202110).

摘　　要：万尼尔构型旨在描述万尼尔函数在实空间上的局域位置及其携带的电荷信息,这一物理概念的提出为刻画天然及人工晶体结构中的波函数提供了全新的视角.在二维高阶拓扑绝缘体中,万尼尔构型中的分数化电荷可以作为一种内禀的拓扑不变量来表征湮灭在体连续谱中的角模式.本文报告了一项基于测量谱电荷分布观测声学体系中万尼尔构型的实验研究.作者在构建的声子晶体中测得了表现为分数化谱电荷的拓扑角模式反常,这种模式反常可以作为一种易于观测的实空间拓扑指标对湮灭在体态中的拓扑角模式进行先验判别.在此基础上,通过将不同的万尼尔构型按照多种方式进行组合,将原本湮没在体连续谱中的角模式调制至带隙中.在组合后的声子晶体中,平庸相和非平庸相结构均可以作为包覆层,从而为在带隙中构造和调控拓扑角模式提供了一种新思路.该研究有望应用于设计高品质因子声谐振腔、声通信以及传感增强等领域.Wannier configuration,which is the real-space distribution of the spatial locations of symmetric Wannier functions(SWFs),provides a new viewpoint for the wave motions in crystalline structures.In Wannier configurations,the deviation of the spatial location of SWF from the unit-cell center often indicates the existence of nontrivial boundary signatures.Moreover,the excess charges extracted from Wannier configuration constitute genuine topological indicators in real space[1,2].

关 键 词：拓扑绝缘体 人工晶体 电荷分布 连续谱 声子晶体 尼尔 声学 拓扑不变量 

分 类 号：O735[理学—晶体学] O469