Geometry-dependent skin effects in reciprocal photonic crystals
Skin effect that all eigenmodes within a frequency range become edge states is dictated by the topological properties of complex eigenvalues unique in non-Hermitian systems. The prevailing attempts to realize such a fascinating effect are confined to either one-dimensional or nonreciprocal systems e...
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| Language: | English |
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De Gruyter
2022-06-01
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| Series: | Nanophotonics |
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| Online Access: | https://doi.org/10.1515/nanoph-2022-0211 |
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| author | Fang Zhening Hu Mengying Zhou Lei Ding Kun |
| author_facet | Fang Zhening Hu Mengying Zhou Lei Ding Kun |
| author_sort | Fang Zhening |
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| description | Skin effect that all eigenmodes within a frequency range become edge states is dictated by the topological properties of complex eigenvalues unique in non-Hermitian systems. The prevailing attempts to realize such a fascinating effect are confined to either one-dimensional or nonreciprocal systems exhibiting asymmetric couplings. Here, inspired by a recent model Hamiltonian theory, we propose a realistic reciprocal two-dimensional (2D) photonic crystal (PhC) system that shows the desired skin effect. Specifically, we establish a routine for designing such non-Hermitian systems via revealing the inherent connections between the nontrivial eigenvalue topology of order-2 exceptional points (EPs) and the skin effects. Guided by the proposed strategy, we successfully design a 2D PhC that possesses the EPs with nonzero eigenvalue winding numbers. The spectral area along a specific wavevector direction is then formed by leveraging the symmetry of the macroscopic geometry and the unit cell. The projected-band-structure calculations are performed to demonstrate that the desired skin effect exists at the specific crystalline interfaces. We finally employ time-domain simulations to vividly illustrate this phenomenon by exciting a pulse at the center of a finite-sized PhC. Our results form a solid basis for further experimental confirmations and applications of the skin effect. |
| format | Article |
| id | doaj-art-35164f4525a3430cbf3e8c7d85be25ac |
| institution | Kabale University |
| issn | 2192-8614 |
| language | English |
| publishDate | 2022-06-01 |
| publisher | De Gruyter |
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| series | Nanophotonics |
| spelling | doaj-art-35164f4525a3430cbf3e8c7d85be25ac2024-11-25T11:19:07ZengDe GruyterNanophotonics2192-86142022-06-0111153447345610.1515/nanoph-2022-0211Geometry-dependent skin effects in reciprocal photonic crystalsFang Zhening0Hu Mengying1Zhou Lei2Ding Kun3Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai200438, ChinaDepartment of Physics, State Key Laboratory of Surface Physics, and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai200438, ChinaDepartment of Physics, State Key Laboratory of Surface Physics, and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai200438, ChinaDepartment of Physics, State Key Laboratory of Surface Physics, and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai200438, ChinaSkin effect that all eigenmodes within a frequency range become edge states is dictated by the topological properties of complex eigenvalues unique in non-Hermitian systems. The prevailing attempts to realize such a fascinating effect are confined to either one-dimensional or nonreciprocal systems exhibiting asymmetric couplings. Here, inspired by a recent model Hamiltonian theory, we propose a realistic reciprocal two-dimensional (2D) photonic crystal (PhC) system that shows the desired skin effect. Specifically, we establish a routine for designing such non-Hermitian systems via revealing the inherent connections between the nontrivial eigenvalue topology of order-2 exceptional points (EPs) and the skin effects. Guided by the proposed strategy, we successfully design a 2D PhC that possesses the EPs with nonzero eigenvalue winding numbers. The spectral area along a specific wavevector direction is then formed by leveraging the symmetry of the macroscopic geometry and the unit cell. The projected-band-structure calculations are performed to demonstrate that the desired skin effect exists at the specific crystalline interfaces. We finally employ time-domain simulations to vividly illustrate this phenomenon by exciting a pulse at the center of a finite-sized PhC. Our results form a solid basis for further experimental confirmations and applications of the skin effect.https://doi.org/10.1515/nanoph-2022-0211exceptional pointsnon-hermitian skin effectsphotonic crystals |
| spellingShingle | Fang Zhening Hu Mengying Zhou Lei Ding Kun Geometry-dependent skin effects in reciprocal photonic crystals Nanophotonics exceptional points non-hermitian skin effects photonic crystals |
| title | Geometry-dependent skin effects in reciprocal photonic crystals |
| title_full | Geometry-dependent skin effects in reciprocal photonic crystals |
| title_fullStr | Geometry-dependent skin effects in reciprocal photonic crystals |
| title_full_unstemmed | Geometry-dependent skin effects in reciprocal photonic crystals |
| title_short | Geometry-dependent skin effects in reciprocal photonic crystals |
| title_sort | geometry dependent skin effects in reciprocal photonic crystals |
| topic | exceptional points non-hermitian skin effects photonic crystals |
| url | https://doi.org/10.1515/nanoph-2022-0211 |
| work_keys_str_mv | AT fangzhening geometrydependentskineffectsinreciprocalphotoniccrystals AT humengying geometrydependentskineffectsinreciprocalphotoniccrystals AT zhoulei geometrydependentskineffectsinreciprocalphotoniccrystals AT dingkun geometrydependentskineffectsinreciprocalphotoniccrystals |