Polarization-driven band topology evolution in twisted MoTe$_2$ and WSe$_2$
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arXiv
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| Autori principali: | , , , , , |
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| Natura: | Preprint |
| Pubblicazione: |
2023
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| _version_ | 1866910452028538880 |
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| author | Zhang, Xiao-Wei Wang, Chong Liu, Xiaoyu Fan, Yueyao Cao, Ting Xiao, Di |
| author_facet | Zhang, Xiao-Wei Wang, Chong Liu, Xiaoyu Fan, Yueyao Cao, Ting Xiao, Di |
| contents | Motivated by recent experimental observations of opposite Chern numbers in $R$-type twisted MoTe$_2$ and WSe$_2$ homobilayers, we perform large-scale density-functional-theory (DFT) calculations with machine learning force fields to investigate moiré band topology from large to small twist angles in both materials. We find that the Chern numbers of the moiré frontier bands change sign as a function of twist angle, and this change is driven by the competition between moiré ferroelectricity and piezoelectricity. Our large-scale calculations, enabled by machine learning methods, reveal crucial insights into interactions across different scales in twisted bilayer systems. The interplay between atomic-level relaxation effects and moiré-scale electrostatic potential variation opens new avenues for the design of intertwined topological and correlated states, including the possibility of mimicking higher Landau-level physics in the absence of a magnetic field. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2311_12776 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Polarization-driven band topology evolution in twisted MoTe$_2$ and WSe$_2$ Zhang, Xiao-Wei Wang, Chong Liu, Xiaoyu Fan, Yueyao Cao, Ting Xiao, Di Materials Science Mesoscale and Nanoscale Physics Motivated by recent experimental observations of opposite Chern numbers in $R$-type twisted MoTe$_2$ and WSe$_2$ homobilayers, we perform large-scale density-functional-theory (DFT) calculations with machine learning force fields to investigate moiré band topology from large to small twist angles in both materials. We find that the Chern numbers of the moiré frontier bands change sign as a function of twist angle, and this change is driven by the competition between moiré ferroelectricity and piezoelectricity. Our large-scale calculations, enabled by machine learning methods, reveal crucial insights into interactions across different scales in twisted bilayer systems. The interplay between atomic-level relaxation effects and moiré-scale electrostatic potential variation opens new avenues for the design of intertwined topological and correlated states, including the possibility of mimicking higher Landau-level physics in the absence of a magnetic field. |
| title | Polarization-driven band topology evolution in twisted MoTe$_2$ and WSe$_2$ |
| topic | Materials Science Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2311.12776 |