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| Main Authors: | , , |
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| Format: | Preprint |
| Published: |
2023
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2310.19931 |
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| _version_ | 1866929333167194112 |
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| author | Huang, Tsung-Sheng Lunts, Peter Hafezi, Mohammad |
| author_facet | Huang, Tsung-Sheng Lunts, Peter Hafezi, Mohammad |
| contents | Optical excitations in moiré transition metal dichalcogenide bilayers lead to the creation of excitons, as electron-hole bound states, that are generically considered within a Bose-Hubbard framework. Here, we demonstrate that these composite particles obey an angular momentum commutation relation that is generally non-bosonic. This emergent spin description of excitons indicates a limitation to their occupancy on each site, which is substantial in the weak electron-hole binding regime. The effective exciton theory is accordingly a spin Hamiltonian, which further becomes a Hubbard model of emergent bosons subject to an occupancy constraint after a Holstein-Primakoff transformation. We apply our theory to three commonly studied bilayers (MoSe2/WSe2, WSe2/WS2, and WSe2/MoS2) and show that in the relevant parameter regimes their allowed occupancies never exceed three excitons. Our systematic theory provides guidelines for future research on the many-body physics of moiré excitons. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2310_19931 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Non-bosonic moiré excitons Huang, Tsung-Sheng Lunts, Peter Hafezi, Mohammad Mesoscale and Nanoscale Physics Materials Science Strongly Correlated Electrons Quantum Physics Optical excitations in moiré transition metal dichalcogenide bilayers lead to the creation of excitons, as electron-hole bound states, that are generically considered within a Bose-Hubbard framework. Here, we demonstrate that these composite particles obey an angular momentum commutation relation that is generally non-bosonic. This emergent spin description of excitons indicates a limitation to their occupancy on each site, which is substantial in the weak electron-hole binding regime. The effective exciton theory is accordingly a spin Hamiltonian, which further becomes a Hubbard model of emergent bosons subject to an occupancy constraint after a Holstein-Primakoff transformation. We apply our theory to three commonly studied bilayers (MoSe2/WSe2, WSe2/WS2, and WSe2/MoS2) and show that in the relevant parameter regimes their allowed occupancies never exceed three excitons. Our systematic theory provides guidelines for future research on the many-body physics of moiré excitons. |
| title | Non-bosonic moiré excitons |
| topic | Mesoscale and Nanoscale Physics Materials Science Strongly Correlated Electrons Quantum Physics |
| url | https://arxiv.org/abs/2310.19931 |