Nested chirality and multimode transfer around exceptional points driven by external forces in electric circuits
Abstract Exceptional points (EPs) are non-Hermitian degeneracies or branch points where eigenvalues and their corresponding eigenvectors coalesce. Due to the complex non-trivial topology of Riemann surfaces associated with non-Hermitian Hamiltonians, the dynamical encirclement or proximity of EPs in...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-02-01
|
| Series: | Communications Physics |
| Online Access: | https://doi.org/10.1038/s42005-025-01962-0 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1823861959949287424 |
|---|---|
| author | Naiqiao Pan Tian Chen Xiangdong Zhang |
| author_facet | Naiqiao Pan Tian Chen Xiangdong Zhang |
| author_sort | Naiqiao Pan |
| collection | DOAJ |
| description | Abstract Exceptional points (EPs) are non-Hermitian degeneracies or branch points where eigenvalues and their corresponding eigenvectors coalesce. Due to the complex non-trivial topology of Riemann surfaces associated with non-Hermitian Hamiltonians, the dynamical encirclement or proximity of EPs in parameter space has been shown to lead to some novel physical phenomena, such as the chiral modes modulations. However, in the previous studies on dynamically encircling EPs, tuning the chirality for applications requires periodic modulation of the system parameters. Here, we propose theoretically and demonstrate experimentally a way to generate EPs and realize asymmetric multimode switching by tuning external forces. The application of the external force achieves the effect of modifying the system parameters so that the dynamical encircling of the EPs can be easily realized. It is shown theoretically that nested chiral behavior and multimode transfer appear in a two-dimensional non-Hermitian higher-order topological insulator with twofold degenerate second-order EPs by tuning the external forces. Furthermore, we design and fabricate the corresponding circuit networks, and experimentally observe nested chiral behavior and multimode transfer. Our work opens up avenues for practical applications of the non-Hermitian physical phenomena. |
| format | Article |
| id | doaj-art-50558c3406a14db59c329285b6ee6b4c |
| institution | Kabale University |
| issn | 2399-3650 |
| language | English |
| publishDate | 2025-02-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Communications Physics |
| spelling | doaj-art-50558c3406a14db59c329285b6ee6b4c2025-02-09T12:40:38ZengNature PortfolioCommunications Physics2399-36502025-02-018111110.1038/s42005-025-01962-0Nested chirality and multimode transfer around exceptional points driven by external forces in electric circuitsNaiqiao Pan0Tian Chen1Xiangdong Zhang2Key Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of TechnologyKey Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of TechnologyKey Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of TechnologyAbstract Exceptional points (EPs) are non-Hermitian degeneracies or branch points where eigenvalues and their corresponding eigenvectors coalesce. Due to the complex non-trivial topology of Riemann surfaces associated with non-Hermitian Hamiltonians, the dynamical encirclement or proximity of EPs in parameter space has been shown to lead to some novel physical phenomena, such as the chiral modes modulations. However, in the previous studies on dynamically encircling EPs, tuning the chirality for applications requires periodic modulation of the system parameters. Here, we propose theoretically and demonstrate experimentally a way to generate EPs and realize asymmetric multimode switching by tuning external forces. The application of the external force achieves the effect of modifying the system parameters so that the dynamical encircling of the EPs can be easily realized. It is shown theoretically that nested chiral behavior and multimode transfer appear in a two-dimensional non-Hermitian higher-order topological insulator with twofold degenerate second-order EPs by tuning the external forces. Furthermore, we design and fabricate the corresponding circuit networks, and experimentally observe nested chiral behavior and multimode transfer. Our work opens up avenues for practical applications of the non-Hermitian physical phenomena.https://doi.org/10.1038/s42005-025-01962-0 |
| spellingShingle | Naiqiao Pan Tian Chen Xiangdong Zhang Nested chirality and multimode transfer around exceptional points driven by external forces in electric circuits Communications Physics |
| title | Nested chirality and multimode transfer around exceptional points driven by external forces in electric circuits |
| title_full | Nested chirality and multimode transfer around exceptional points driven by external forces in electric circuits |
| title_fullStr | Nested chirality and multimode transfer around exceptional points driven by external forces in electric circuits |
| title_full_unstemmed | Nested chirality and multimode transfer around exceptional points driven by external forces in electric circuits |
| title_short | Nested chirality and multimode transfer around exceptional points driven by external forces in electric circuits |
| title_sort | nested chirality and multimode transfer around exceptional points driven by external forces in electric circuits |
| url | https://doi.org/10.1038/s42005-025-01962-0 |
| work_keys_str_mv | AT naiqiaopan nestedchiralityandmultimodetransferaroundexceptionalpointsdrivenbyexternalforcesinelectriccircuits AT tianchen nestedchiralityandmultimodetransferaroundexceptionalpointsdrivenbyexternalforcesinelectriccircuits AT xiangdongzhang nestedchiralityandmultimodetransferaroundexceptionalpointsdrivenbyexternalforcesinelectriccircuits |