Engineering Miniband Topology via Band-Folding in Moiré Superlattice Materials
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| Main Authors: | , , , |
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| Format: | Preprint |
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2024
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| _version_ | 1866917672635072512 |
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| author | Yang, Kaijie Liu, Yunzhe Schindler, Frank Liu, Chao-Xing |
| author_facet | Yang, Kaijie Liu, Yunzhe Schindler, Frank Liu, Chao-Xing |
| contents | The emergence of topologically non-trivial flat bands in moiré materials provides an opportunity to explore the interplay between topological physics and correlation effects, leading to the recent experimental realization of interacting topological phases, e.g. fractional Chern insulators. In this work, we propose a mechanism of band inversion induced by band-folding from the moiré superlattice potential for engineering topological minibands in moiré materials. We illustrate this mechanism via two classes of model Hamiltonians, namely the Rashba model and the Bernevig-Hughes-Zhang (BHZ) model, under the moiré superlattice potentials. Moiré minibands with non-trivial band topology, including Z2 number, mirror Chern number and fragile topology, have been found and the topological phase diagram is constructed for these moiré models. A general theory based on band representations in the morié Brillouin zone is also developed for a generalization of this mechanism to other space groups. Possible experimental realizations of our model Hamiltonian are discussed. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2405_13145 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Engineering Miniband Topology via Band-Folding in Moiré Superlattice Materials Yang, Kaijie Liu, Yunzhe Schindler, Frank Liu, Chao-Xing Mesoscale and Nanoscale Physics The emergence of topologically non-trivial flat bands in moiré materials provides an opportunity to explore the interplay between topological physics and correlation effects, leading to the recent experimental realization of interacting topological phases, e.g. fractional Chern insulators. In this work, we propose a mechanism of band inversion induced by band-folding from the moiré superlattice potential for engineering topological minibands in moiré materials. We illustrate this mechanism via two classes of model Hamiltonians, namely the Rashba model and the Bernevig-Hughes-Zhang (BHZ) model, under the moiré superlattice potentials. Moiré minibands with non-trivial band topology, including Z2 number, mirror Chern number and fragile topology, have been found and the topological phase diagram is constructed for these moiré models. A general theory based on band representations in the morié Brillouin zone is also developed for a generalization of this mechanism to other space groups. Possible experimental realizations of our model Hamiltonian are discussed. |
| title | Engineering Miniband Topology via Band-Folding in Moiré Superlattice Materials |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2405.13145 |