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| Main Authors: | , |
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| Format: | Preprint |
| Published: |
2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2502.16551 |
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| _version_ | 1866912529128620032 |
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| author | Sato, Taiki Ishizuka, Hiroaki |
| author_facet | Sato, Taiki Ishizuka, Hiroaki |
| contents | Using a microscopic model, we show that the electron-electron interaction of flat bands deviates significantly from the Coulomb interaction. In particular, we find that large-momentum scattering is enhanced at $θ\lesssim4^\circ$, with a non-monotonic momentum dependence appearing near the magic angle. For $θ\gtrsim 1.2^\circ$, the enhanced large-momentum scattering can be attributed to the compact Wannier function. On the other hand, for $θ\lesssim1.2^\circ$, the nonmonotonic momentum dependence of the interaction matrix cannot be explained by a simple Wannier orbital, indicating a nontrivial modification to the el-el interaction. Notably, the range of angles $θ$ where the large-momentum scattering is enhanced differs from the magic angles at which nearly-flat bands emerge, suggesting that the angle dependence of material properties provides information about the effect of interaction. The results highlight unusual features of the interaction in moiré graphene. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2502_16551 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Anomalous enhancement of large-momentum scattering by electron-electron interaction in moiré superlattices Sato, Taiki Ishizuka, Hiroaki Mesoscale and Nanoscale Physics Using a microscopic model, we show that the electron-electron interaction of flat bands deviates significantly from the Coulomb interaction. In particular, we find that large-momentum scattering is enhanced at $θ\lesssim4^\circ$, with a non-monotonic momentum dependence appearing near the magic angle. For $θ\gtrsim 1.2^\circ$, the enhanced large-momentum scattering can be attributed to the compact Wannier function. On the other hand, for $θ\lesssim1.2^\circ$, the nonmonotonic momentum dependence of the interaction matrix cannot be explained by a simple Wannier orbital, indicating a nontrivial modification to the el-el interaction. Notably, the range of angles $θ$ where the large-momentum scattering is enhanced differs from the magic angles at which nearly-flat bands emerge, suggesting that the angle dependence of material properties provides information about the effect of interaction. The results highlight unusual features of the interaction in moiré graphene. |
| title | Anomalous enhancement of large-momentum scattering by electron-electron interaction in moiré superlattices |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2502.16551 |