Exciton fine structure in twisted transition metal dichalcogenide heterostructures
Abstract Moiré superlattices of transition metal dichalcogenide (TMD) heterostructures give rise to rich excitonic phenomena associated with the interlayer twist angle. Theoretical calculations of excitons in such systems are typically based on model moiré potentials that mitigate the computational...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-10-01
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| Series: | npj Computational Materials |
| Online Access: | https://doi.org/10.1038/s41524-023-01145-x |
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| author | Sudipta Kundu Tomer Amit H. R. Krishnamurthy Manish Jain Sivan Refaely-Abramson |
| author_facet | Sudipta Kundu Tomer Amit H. R. Krishnamurthy Manish Jain Sivan Refaely-Abramson |
| author_sort | Sudipta Kundu |
| collection | DOAJ |
| description | Abstract Moiré superlattices of transition metal dichalcogenide (TMD) heterostructures give rise to rich excitonic phenomena associated with the interlayer twist angle. Theoretical calculations of excitons in such systems are typically based on model moiré potentials that mitigate the computational cost. However, predictive understanding of the electron-hole coupling dominating the excitations is crucial to realize the twist-induced modifications of the optical selection rules. In this work, we use many-body perturbation theory to evaluate the relation between twist angle and exciton properties in TMD heterostructures. We present an approach for unfolding excitonic states from the moiré Brillouin zone onto the separate-layer ones. Applying this method to a large-angle twisted MoS2/MoSe2 bilayer, we find that the optical spectrum is dominated by mixed electron–hole transitions with different momenta in the separate monolayers, leading to unexpected hybridization between interlayer and intralayer excitons. Our findings offer a design pathway for exciton layer-localization in TMD heterostructures. |
| format | Article |
| id | doaj-art-f09a8f4ed58249d3bddc697c9e903dc6 |
| institution | Kabale University |
| issn | 2057-3960 |
| language | English |
| publishDate | 2023-10-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | npj Computational Materials |
| spelling | doaj-art-f09a8f4ed58249d3bddc697c9e903dc62024-12-08T12:37:40ZengNature Portfolionpj Computational Materials2057-39602023-10-01911710.1038/s41524-023-01145-xExciton fine structure in twisted transition metal dichalcogenide heterostructuresSudipta Kundu0Tomer Amit1H. R. Krishnamurthy2Manish Jain3Sivan Refaely-Abramson4Centre for Condensed Matter Theory, Department of Physics, Indian Institute of ScienceDepartment of Molecular Chemistry and Materials Science, Weizmann Institute of ScienceCentre for Condensed Matter Theory, Department of Physics, Indian Institute of ScienceCentre for Condensed Matter Theory, Department of Physics, Indian Institute of ScienceDepartment of Molecular Chemistry and Materials Science, Weizmann Institute of ScienceAbstract Moiré superlattices of transition metal dichalcogenide (TMD) heterostructures give rise to rich excitonic phenomena associated with the interlayer twist angle. Theoretical calculations of excitons in such systems are typically based on model moiré potentials that mitigate the computational cost. However, predictive understanding of the electron-hole coupling dominating the excitations is crucial to realize the twist-induced modifications of the optical selection rules. In this work, we use many-body perturbation theory to evaluate the relation between twist angle and exciton properties in TMD heterostructures. We present an approach for unfolding excitonic states from the moiré Brillouin zone onto the separate-layer ones. Applying this method to a large-angle twisted MoS2/MoSe2 bilayer, we find that the optical spectrum is dominated by mixed electron–hole transitions with different momenta in the separate monolayers, leading to unexpected hybridization between interlayer and intralayer excitons. Our findings offer a design pathway for exciton layer-localization in TMD heterostructures.https://doi.org/10.1038/s41524-023-01145-x |
| spellingShingle | Sudipta Kundu Tomer Amit H. R. Krishnamurthy Manish Jain Sivan Refaely-Abramson Exciton fine structure in twisted transition metal dichalcogenide heterostructures npj Computational Materials |
| title | Exciton fine structure in twisted transition metal dichalcogenide heterostructures |
| title_full | Exciton fine structure in twisted transition metal dichalcogenide heterostructures |
| title_fullStr | Exciton fine structure in twisted transition metal dichalcogenide heterostructures |
| title_full_unstemmed | Exciton fine structure in twisted transition metal dichalcogenide heterostructures |
| title_short | Exciton fine structure in twisted transition metal dichalcogenide heterostructures |
| title_sort | exciton fine structure in twisted transition metal dichalcogenide heterostructures |
| url | https://doi.org/10.1038/s41524-023-01145-x |
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