Gate-tunable antiferromagnetic Chern insulator in twisted bilayer transition metal dichalcogenides
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| Main Authors: | , , , , |
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| Format: | Preprint |
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2023
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| _version_ | 1866910408665726976 |
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| author | Liu, Xiaoyu Wang, Chong Zhang, Xiao-Wei Cao, Ting Xiao, Di |
| author_facet | Liu, Xiaoyu Wang, Chong Zhang, Xiao-Wei Cao, Ting Xiao, Di |
| contents | A series of recent experimental works on twisted MoTe$_2$ homobilayers have unveiled an abundance of exotic states in this system. Valley-polarized quantum anomalous Hall states have been identified at hole doping of $ν= -1$, and the fractional quantum anomalous Hall effect is observed at $ν= -2/3$ and $ν= -3/5$. In this work, we investigate the electronic properties of AA-stacked twisted bilayer MoTe$_2$ at $ν=-2$ by $k$-space Hartree-Fock calculations. We find that the phase diagram is qualitatively similar to the phase diagram of a Kane-Mele-Hubbard with staggered onsite potential. A noteworthy phase within the diagram is the antiferromagnetic Chern insulator, stabilized by the external electric field. We attribute the existence of this Chern insulator to an antiferromagnetic instability at a topological phase transition between the quantum spin hall phase and a band insulator phase. We highlight that the antiferromagnetic Chern insulator phase is most evident at a twist angle of approximately $4^\circ$. Our research proposes the potential of realizing a Chern insulator beyond $ν=-1$, and contributes fresh perspectives on the interplay between band topology and electron-electron correlations in moiré superlattices. |
| format | Preprint |
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arxiv_https___arxiv_org_abs_2308_07488 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Gate-tunable antiferromagnetic Chern insulator in twisted bilayer transition metal dichalcogenides Liu, Xiaoyu Wang, Chong Zhang, Xiao-Wei Cao, Ting Xiao, Di Mesoscale and Nanoscale Physics A series of recent experimental works on twisted MoTe$_2$ homobilayers have unveiled an abundance of exotic states in this system. Valley-polarized quantum anomalous Hall states have been identified at hole doping of $ν= -1$, and the fractional quantum anomalous Hall effect is observed at $ν= -2/3$ and $ν= -3/5$. In this work, we investigate the electronic properties of AA-stacked twisted bilayer MoTe$_2$ at $ν=-2$ by $k$-space Hartree-Fock calculations. We find that the phase diagram is qualitatively similar to the phase diagram of a Kane-Mele-Hubbard with staggered onsite potential. A noteworthy phase within the diagram is the antiferromagnetic Chern insulator, stabilized by the external electric field. We attribute the existence of this Chern insulator to an antiferromagnetic instability at a topological phase transition between the quantum spin hall phase and a band insulator phase. We highlight that the antiferromagnetic Chern insulator phase is most evident at a twist angle of approximately $4^\circ$. Our research proposes the potential of realizing a Chern insulator beyond $ν=-1$, and contributes fresh perspectives on the interplay between band topology and electron-electron correlations in moiré superlattices. |
| title | Gate-tunable antiferromagnetic Chern insulator in twisted bilayer transition metal dichalcogenides |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2308.07488 |