Characterizing non-Hermitian topological monomodes via fractional mode charges in acoustic systems  

作　　者：Taotao Zheng Wenbin Lv Yuxiang Zhou Chudong Xu Ming-Hui Lu 

机构地区：[1]College of Electronic Engineering,South China Agricultural University,Guangzhou 510642,China [2]College of Engineering and Applied Sciences and National Laboratory of Solid State Microstructures,Nanjing University,Nanjing 210093,China

出　　处：《Frontiers of physics》2025年第1期195-203,共9页物理学前沿(英文版)

基　　金：support of the Natural Science Foundation of Guangdong,China(No.2020A1515010634).

摘　　要：Non-Hermitian properties play an important role in topological acoustic systems,which can not only change the band topology but may also lead to novel applications such as non-Hermitian skin effect(NHSE).However,non-Hermitian systems,which are more closely related to real-world systems due to inevitable losses or gains,present challenges to topological classifications and boundary correspondence.Here,we demonstrate a topological monomodes based on one-dimensional(1D)Su-Schrieffer-Heeger(SSH)chains subject to non-Hermitian loss influences,which is achieved through tuning and introducing loss in the coupled acoustic cavity system.Moreover,we have extended this phenomenon from lowdimensional to high-dimensional systems.Theoretical and simulation results indicate that monomode can still be observed in non-Hermitian acoustic high-dimensional models,challenging the notion that topological states can only occur in pairs.More importantly,we have simulated the acoustic topological monomodes under non-Hermitian high-dimensional systems using acoustic local density of states(LDOS).Theoretical and simulation results demonstrate that local density of states can be used to calculate fractional charge modes and characterize topological monomodes in non-Hermitian acoustic systems.Our findings may have significant implications for the characterization of topology in non-Hermitian acoustic systems.This discovery offers a new perspective and approach to the study of non-Hermitian acoustic topology.

关 键 词：topological monomodes non-Hermitian system local density of states 

分 类 号：O17[理学—数学]