Non-Hermitian topological coupler for elastic waves

• 作者: Yan Meng Xiaoxiao Wu Yaxi Shen Dong Liu Zixian Liang Xiang Zhang Jensen Li
• 来源期刊: 中国科学：物理学 力学 天文学（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: Article
• 页码范围: 57-65
• 页数: 9页
• 语种: 英文

摘要

Non-Hermitian topological systems,by combining the advantages of topological robustness and sensitivity induced by non-Hermiticity,have recently emerged and attracted much research interest.Here,we propose a device based on the topological coupler in elastic waves with non-Hermiticity,which contains two topological domain walls and four ports.In this device,topological robustness routes the transmission of waves,while non-Hermiticity controls the gain or loss of waves as they propagate.These mechanisms result in continuous and quantitative control of the energy distribution ratio of each port.A non-Hermitian Hamiltonian is introduced to reveal the coupling mechanism of the topological coupler,and a scattering matrix is proposed to predict the energy distribution ratio of each port.The proposed topological coupler,which provides a new paradigm for the non-Hermitian topological systems,can be employed as a sensitive beam splitter or a coupler switch.Moreover,the topological coupler has potential applications in information processing and logic operation in elastic circuits or networks,and the paradigm also applies to other classical systems.