Nearly flat Chern bands in moiré superlattices
Topology and electron interactions are two central themes in modern condensed matter physics. Here, we propose graphene-based systems where both the band topology and interaction effects can be simply controlled with electric fields. We study a number of systems of twisted double layers with small t...
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| Format: | Article |
| Language: | English |
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American Physical Society
2019
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| Online Access: | http://hdl.handle.net/1721.1/120523 https://orcid.org/0000-0001-9493-1743 https://orcid.org/0000-0002-9000-4501 https://orcid.org/0000-0001-8217-8213 https://orcid.org/0000-0003-4203-4148 |
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| author | Zhang, Yahui Mao, Dan Cao, Yuan Jarillo-Herrero, Pablo Todadri, Senthil |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Zhang, Yahui Mao, Dan Cao, Yuan Jarillo-Herrero, Pablo Todadri, Senthil |
| author_sort | Zhang, Yahui |
| collection | MIT |
| description | Topology and electron interactions are two central themes in modern condensed matter physics. Here, we propose graphene-based systems where both the band topology and interaction effects can be simply controlled with electric fields. We study a number of systems of twisted double layers with small twist angle where a moiré superlattice is formed. Each layer is chosen to be either AB-stacked bilayer graphene, ABC-stacked trilayer graphene, or hexagonal boron nitride. In these systems, a vertical applied electric field enables control of the bandwidth, and interestingly also the Chern number. We find that the Chern numbers of the bands associated with each of the two microscopic valleys can be ±0,±1,±2,±3 depending on the specific system and vertical electrical field. We show that these graphene moiré superlattices are promising platforms to realize a number of fascinating many-body phenomena, including (fractional) quantum anomalous Hall effects. We also discuss conceptual similarities and implications for modeling twisted bilayer graphene systems. |
| first_indexed | 2024-09-23T16:57:21Z |
| format | Article |
| id | mit-1721.1/120523 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T16:57:21Z |
| publishDate | 2019 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/1205232022-10-03T09:24:06Z Nearly flat Chern bands in moiré superlattices Zhang, Yahui Mao, Dan Cao, Yuan Jarillo-Herrero, Pablo Todadri, Senthil Massachusetts Institute of Technology. Department of Physics Zhang, Yahui Mao, Dan Cao, Yuan Jarillo-Herrero, Pablo Todadri, Senthil Topology and electron interactions are two central themes in modern condensed matter physics. Here, we propose graphene-based systems where both the band topology and interaction effects can be simply controlled with electric fields. We study a number of systems of twisted double layers with small twist angle where a moiré superlattice is formed. Each layer is chosen to be either AB-stacked bilayer graphene, ABC-stacked trilayer graphene, or hexagonal boron nitride. In these systems, a vertical applied electric field enables control of the bandwidth, and interestingly also the Chern number. We find that the Chern numbers of the bands associated with each of the two microscopic valleys can be ±0,±1,±2,±3 depending on the specific system and vertical electrical field. We show that these graphene moiré superlattices are promising platforms to realize a number of fascinating many-body phenomena, including (fractional) quantum anomalous Hall effects. We also discuss conceptual similarities and implications for modeling twisted bilayer graphene systems. National Science Foundation (U.S.) (Grant DMR-1608505) Simons Foundation (Simons Investigator Award) Gordon and Betty Moore Foundation (Grant GBMF4541) STC Center for Integrated Quantum Materials (Grant DMR-1231319) 2019-02-21T18:30:32Z 2019-02-21T18:30:32Z 2019-02 2018-12 2019-02-12T18:00:18Z Article http://purl.org/eprint/type/JournalArticle 2469-9950 2469-9969 http://hdl.handle.net/1721.1/120523 Zhang, Ya-Hui, et al. “Nearly Flat Chern Bands in Moiré Superlattices.” Physical Review B, vol. 99, no. 7, Feb. 2019. © 2019 American Physical Society https://orcid.org/0000-0001-9493-1743 https://orcid.org/0000-0002-9000-4501 https://orcid.org/0000-0001-8217-8213 https://orcid.org/0000-0003-4203-4148 en http://dx.doi.org/10.1103/PhysRevB.99.075127 Physical Review B Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. American Physical Society application/pdf American Physical Society American Physical Society |
| spellingShingle | Zhang, Yahui Mao, Dan Cao, Yuan Jarillo-Herrero, Pablo Todadri, Senthil Nearly flat Chern bands in moiré superlattices |
| title | Nearly flat Chern bands in moiré superlattices |
| title_full | Nearly flat Chern bands in moiré superlattices |
| title_fullStr | Nearly flat Chern bands in moiré superlattices |
| title_full_unstemmed | Nearly flat Chern bands in moiré superlattices |
| title_short | Nearly flat Chern bands in moiré superlattices |
| title_sort | nearly flat chern bands in moire superlattices |
| url | http://hdl.handle.net/1721.1/120523 https://orcid.org/0000-0001-9493-1743 https://orcid.org/0000-0002-9000-4501 https://orcid.org/0000-0001-8217-8213 https://orcid.org/0000-0003-4203-4148 |
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