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| Natura: | Preprint |
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2022
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| Accesso online: | https://arxiv.org/abs/2206.11666 |
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| _version_ | 1866911971554623488 |
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| author | Xie, Ying-Ming Zhang, Cheng-Ping Law, K. T. |
| author_facet | Xie, Ying-Ming Zhang, Cheng-Ping Law, K. T. |
| contents | Recently, a quantum anomalous Hall (QAH) state was observed in AB stacked moiré MoTe$_2$/WSe$_2$ heterobilayers at half-filling. More recent layer-resolved magnetic circular dichroism (MCD) measurements revealed that spin-polarized moiré bands from both the MoTe$_2$ and the WSe$_2$ layers are involved at the formation of the QAH state. This scenario is not expected by existing theories. In this work, we suggest that the observed QAH state is a new state of matter, namely, a topological $p_x+ip_y$ inter-valley coherent state (TIVC). We point out that the massive Dirac spectrum of the MoTe$_2$ moiré bands, together with the Hund's interaction and the Coulomb interactions give rise to this novel QAH state. Through a self-consistent Hartree-Fock analysis, we find a wide range of interaction strengths and displacement fields that the $p_x+ip_y$-pairing phase is energetically favourable. Besides explaining several key features of the experiments, our theory predicts that the order parameter would involve the pairing of electrons and holes with a definite momentum mismatch such that the pairing would generate a new unit cell which is three times the size of the original moiré unit cell, due to the order parameter modulations. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2206_11666 |
| institution | arXiv |
| publishDate | 2022 |
| record_format | arxiv |
| spellingShingle | Topological $p_x+ip_y$ inter-valley coherent state in Moiré MoTe$_2$/WSe$_2$ heterobilayers Xie, Ying-Ming Zhang, Cheng-Ping Law, K. T. Materials Science Mesoscale and Nanoscale Physics Strongly Correlated Electrons Recently, a quantum anomalous Hall (QAH) state was observed in AB stacked moiré MoTe$_2$/WSe$_2$ heterobilayers at half-filling. More recent layer-resolved magnetic circular dichroism (MCD) measurements revealed that spin-polarized moiré bands from both the MoTe$_2$ and the WSe$_2$ layers are involved at the formation of the QAH state. This scenario is not expected by existing theories. In this work, we suggest that the observed QAH state is a new state of matter, namely, a topological $p_x+ip_y$ inter-valley coherent state (TIVC). We point out that the massive Dirac spectrum of the MoTe$_2$ moiré bands, together with the Hund's interaction and the Coulomb interactions give rise to this novel QAH state. Through a self-consistent Hartree-Fock analysis, we find a wide range of interaction strengths and displacement fields that the $p_x+ip_y$-pairing phase is energetically favourable. Besides explaining several key features of the experiments, our theory predicts that the order parameter would involve the pairing of electrons and holes with a definite momentum mismatch such that the pairing would generate a new unit cell which is three times the size of the original moiré unit cell, due to the order parameter modulations. |
| title | Topological $p_x+ip_y$ inter-valley coherent state in Moiré MoTe$_2$/WSe$_2$ heterobilayers |
| topic | Materials Science Mesoscale and Nanoscale Physics Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2206.11666 |