Strain-enhanced two-photon absorption in twisted bilayer graphene
Abstract We theoretically investigate the strain-tuned moiré flat bands and two-photon absorption (TPA) in magic-angle (MA) twisted bilayer graphene (TBG). Using a low-energy continuum model for strained TBG and second-order perturbation theory, we demonstrate that uniaxial strain significantly modu...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2025-05-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-025-00158-4 |
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| author | Lianmeng Yu Zhaoming Fu Peizhi Yang Xiaobo Feng |
| author_facet | Lianmeng Yu Zhaoming Fu Peizhi Yang Xiaobo Feng |
| author_sort | Lianmeng Yu |
| collection | DOAJ |
| description | Abstract We theoretically investigate the strain-tuned moiré flat bands and two-photon absorption (TPA) in magic-angle (MA) twisted bilayer graphene (TBG). Using a low-energy continuum model for strained TBG and second-order perturbation theory, we demonstrate that uniaxial strain significantly modulates both electronic and optical properties. Strain magnitude controls the flat band separation, while strain direction induces periodic variations in the band structure. The TPA spectra reveal strain-dependent features: intraband transitions dominate at higher strains, enhancing the absorption coefficient by an order of magnitude, while interband transitions exhibit characteristic spectral shifts. Notably, smaller strain direction angles yield larger TPA coefficients with red-shifted peaks. These results provide fundamental insights for developing strain-tunable optoelectronic devices based on moiré materials. |
| format | Article |
| id | doaj-art-ac28a211fa9c4fea893d4af86e34c61d |
| institution | Kabale University |
| issn | 2045-2322 |
| language | English |
| publishDate | 2025-05-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj-art-ac28a211fa9c4fea893d4af86e34c61d2025-08-20T03:52:23ZengNature PortfolioScientific Reports2045-23222025-05-0115111010.1038/s41598-025-00158-4Strain-enhanced two-photon absorption in twisted bilayer grapheneLianmeng Yu0Zhaoming Fu1Peizhi Yang2Xiaobo Feng3School of Physics and Electronic Information, Yunnan Normal UniversitySchool of Physics and Electronic Information, Yunnan Normal UniversityKey Laboratory of Advanced Technique and Preparation for Renewable Energy Materials, Ministry of Education, Yunnan Normal UniversitySchool of Physics and Electronic Information, Yunnan Normal UniversityAbstract We theoretically investigate the strain-tuned moiré flat bands and two-photon absorption (TPA) in magic-angle (MA) twisted bilayer graphene (TBG). Using a low-energy continuum model for strained TBG and second-order perturbation theory, we demonstrate that uniaxial strain significantly modulates both electronic and optical properties. Strain magnitude controls the flat band separation, while strain direction induces periodic variations in the band structure. The TPA spectra reveal strain-dependent features: intraband transitions dominate at higher strains, enhancing the absorption coefficient by an order of magnitude, while interband transitions exhibit characteristic spectral shifts. Notably, smaller strain direction angles yield larger TPA coefficients with red-shifted peaks. These results provide fundamental insights for developing strain-tunable optoelectronic devices based on moiré materials.https://doi.org/10.1038/s41598-025-00158-4 |
| spellingShingle | Lianmeng Yu Zhaoming Fu Peizhi Yang Xiaobo Feng Strain-enhanced two-photon absorption in twisted bilayer graphene Scientific Reports |
| title | Strain-enhanced two-photon absorption in twisted bilayer graphene |
| title_full | Strain-enhanced two-photon absorption in twisted bilayer graphene |
| title_fullStr | Strain-enhanced two-photon absorption in twisted bilayer graphene |
| title_full_unstemmed | Strain-enhanced two-photon absorption in twisted bilayer graphene |
| title_short | Strain-enhanced two-photon absorption in twisted bilayer graphene |
| title_sort | strain enhanced two photon absorption in twisted bilayer graphene |
| url | https://doi.org/10.1038/s41598-025-00158-4 |
| work_keys_str_mv | AT lianmengyu strainenhancedtwophotonabsorptionintwistedbilayergraphene AT zhaomingfu strainenhancedtwophotonabsorptionintwistedbilayergraphene AT peizhiyang strainenhancedtwophotonabsorptionintwistedbilayergraphene AT xiaobofeng strainenhancedtwophotonabsorptionintwistedbilayergraphene |