{"title":"A scheme for realizing nonreciprocal interlayer coupling in bilayer topological systems.","authors":"Xiaoxiao Wang, Ruizhe Gu, Yandong Li, Huixin Qi, Xiaoyong Hu, Xingyuan Wang, Qihuang Gong","doi":"10.1007/s12200-023-00094-z","DOIUrl":null,"url":null,"abstract":"<p><p>Nonreciprocal interlayer coupling is difficult to practically implement in bilayer non-Hermitian topological photonic systems. In this work, we identify a similarity transformation between the Hamiltonians of systems with nonreciprocal interlayer coupling and on-site gain/loss. The similarity transformation is widely applicable, and we show its application in one- and two-dimensional bilayer topological systems as examples. The bilayer non-Hermitian system with nonreciprocal interlayer coupling, whose topological number can be defined using the gauge-smoothed Wilson loop, is topologically equivalent to the bilayer system with on-site gain/loss. We also show that the topological number of bilayer non-Hermitian C<sub>6v</sub>-typed domain-induced topological interface states can be defined in the same way as in the case of the bilayer non-Hermitian Su-Schrieffer-Heeger model. Our results show the relations between two microscopic provenances of the non-Hermiticity and provide a universal and convenient scheme for constructing and studying nonreciprocal interlayer coupling in bilayer non-Hermitian topological systems. This scheme is useful for observation of non-Hermitian skin effect in three-dimensional systems.</p>","PeriodicalId":12685,"journal":{"name":"Frontiers of Optoelectronics","volume":"16 1","pages":"38"},"PeriodicalIF":4.1000,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10682335/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers of Optoelectronics","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1007/s12200-023-00094-z","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
Nonreciprocal interlayer coupling is difficult to practically implement in bilayer non-Hermitian topological photonic systems. In this work, we identify a similarity transformation between the Hamiltonians of systems with nonreciprocal interlayer coupling and on-site gain/loss. The similarity transformation is widely applicable, and we show its application in one- and two-dimensional bilayer topological systems as examples. The bilayer non-Hermitian system with nonreciprocal interlayer coupling, whose topological number can be defined using the gauge-smoothed Wilson loop, is topologically equivalent to the bilayer system with on-site gain/loss. We also show that the topological number of bilayer non-Hermitian C6v-typed domain-induced topological interface states can be defined in the same way as in the case of the bilayer non-Hermitian Su-Schrieffer-Heeger model. Our results show the relations between two microscopic provenances of the non-Hermiticity and provide a universal and convenient scheme for constructing and studying nonreciprocal interlayer coupling in bilayer non-Hermitian topological systems. This scheme is useful for observation of non-Hermitian skin effect in three-dimensional systems.
期刊介绍:
Frontiers of Optoelectronics seeks to provide a multidisciplinary forum for a broad mix of peer-reviewed academic papers in order to promote rapid communication and exchange between researchers in China and abroad. It introduces and reflects significant achievements being made in the field of photonics or optoelectronics. The topics include, but are not limited to, semiconductor optoelectronics, nano-photonics, information photonics, energy photonics, ultrafast photonics, biomedical photonics, nonlinear photonics, fiber optics, laser and terahertz technology and intelligent photonics. The journal publishes reviews, research articles, letters, comments, special issues and so on.
Frontiers of Optoelectronics especially encourages papers from new emerging and multidisciplinary areas, papers reflecting the international trends of research and development, and on special topics reporting progress made in the field of optoelectronics. All published papers will reflect the original thoughts of researchers and practitioners on basic theories, design and new technology in optoelectronics.
Frontiers of Optoelectronics is strictly peer-reviewed and only accepts original submissions in English. It is a fully OA journal and the APCs are covered by Higher Education Press and Huazhong University of Science and Technology.
● Presents the latest developments in optoelectronics and optics
● Emphasizes the latest developments of new optoelectronic materials, devices, systems and applications
● Covers industrial photonics, information photonics, biomedical photonics, energy photonics, laser and terahertz technology, and more