基于非厄米声学超材料的宽带相干完美吸收  

Broadband coherent perfect absorption based on non-Hermitian acoustic metamaterial

作　　者：严雨婷 杨京[1] 梁彬[1] 程建春[1] Yan Yuting;Yang Jing;Liang Bin;Cheng Jianchun(Key Laboratory of Modern Acoustics,MOE,Institute of Acoustics,Department of Physics,Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China)

机构地区：[1]南京大学物理学院近代声学教育部重点实验室人工微结构科学与技术协同创新中心,南京210093

出　　处：《仪器仪表学报》2024年第6期54-62,共9页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(12174190)项目资助。

摘　　要：相干完美吸收只能在特定共振频率处或窄带实现完美吸收,这极大地限制了其在实际应用中发挥作用。近年来,非厄米调制和声学超材料的引入为复杂声波操控提供了全新的研究思路,并由此产生了许多在天然结构中难以实现的新颖的波与物质的相互作用。本文提出一种非厄米声学亚波长腔管耦合模型,理论推导并展示了相干完美吸收的演化过程。通过调控系统的非厄米参数实现了两个相干完美吸收的简并,简并处带宽平均因子为12.825,且在输出谱图上观测到与之相应的宽带完美吸收特性。本文工作为基于非厄米声学超材料实现宽带相干完美吸收提供了一种新的途径,同时也为开发用于宽带声吸收、声检测等工程应用领域的新型功能性器件奠定了理论基础。Coherent perfect absorption can only be realized at specific resonant frequencies or in narrow bands,which greatly limits its usefulness in practical applications.In recent years,the introduction of non-Hermitian modulation and acoustic metamaterials has provided new research ideas for complex acoustic wave manipulation,and resulted in many novel wave-matter interactions that are difficult to realize in natural structures.In this paper,we propose a non-Hermitian acoustic subwavelength cavity-tube coupling model to theoretically derive and demonstrate the evolution of coherent perfect absorption.Coalescence of two coherent perfect absorptions with a bandwidth averaging factor of 12.825 is realized by tuning the non-Hermitian parameters of the system,and the corresponding broadband perfect absorbing characteristics are observed on the output spectra.This work provides a new way to realize broadband coherent perfect absorption based on non-Hermitian acoustic metamaterials,and also lays a theoretical foundation for the development of new functional devices for broadband acoustic absorption,acoustic detection and other engineering applications.

关 键 词：非厄米 声超材料 相干完美吸收 宽带 简并 

分 类 号：TH73[机械工程—仪器科学与技术] O424[机械工程—精密仪器及机械]