Landau level degeneracy in twisted bilayer graphene: Role of symmetry breaking
The degeneracy of Landau levels flanking charge neutrality in twisted bilayer graphene is known to change from eightfold to fourfold when the twist angle is reduced to values near the magic angle of ≈1.05º. This degeneracy lifting has been reproduced in experiments by multiple groups and is known to...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2020
|
| Online Access: | https://hdl.handle.net/1721.1/125036 |
| _version_ | 1811087944802369536 |
|---|---|
| author | Zhang, Ya-Hui Po, Hoi Chun Todadri, Senthil |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Zhang, Ya-Hui Po, Hoi Chun Todadri, Senthil |
| author_sort | Zhang, Ya-Hui |
| collection | MIT |
| description | The degeneracy of Landau levels flanking charge neutrality in twisted bilayer graphene is known to change from eightfold to fourfold when the twist angle is reduced to values near the magic angle of ≈1.05º. This degeneracy lifting has been reproduced in experiments by multiple groups and is known to occur even in devices which do not harbor the correlated insulators and superconductors. We propose C[subscript 3]-symmetry breaking as an explanation of such robust degeneracy lifting and support our proposal by numerical results on the Landau-level spectrum in near-magic-angle twisted bilayer graphene. Motivated by recent experiments, we further consider the effect of C[subscript 2]-symmetry breaking on the Landau levels. |
| first_indexed | 2024-09-23T13:54:18Z |
| format | Article |
| id | mit-1721.1/125036 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T13:54:18Z |
| publishDate | 2020 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/1250362022-09-28T16:58:24Z Landau level degeneracy in twisted bilayer graphene: Role of symmetry breaking Zhang, Ya-Hui Po, Hoi Chun Todadri, Senthil Massachusetts Institute of Technology. Department of Physics The degeneracy of Landau levels flanking charge neutrality in twisted bilayer graphene is known to change from eightfold to fourfold when the twist angle is reduced to values near the magic angle of ≈1.05º. This degeneracy lifting has been reproduced in experiments by multiple groups and is known to occur even in devices which do not harbor the correlated insulators and superconductors. We propose C[subscript 3]-symmetry breaking as an explanation of such robust degeneracy lifting and support our proposal by numerical results on the Landau-level spectrum in near-magic-angle twisted bilayer graphene. Motivated by recent experiments, we further consider the effect of C[subscript 2]-symmetry breaking on the Landau levels. United States. Department of Energy (Grant DE-SC0008739) 2020-05-06T13:47:39Z 2020-05-06T13:47:39Z 2019-09 2019-06 2019-09-05T18:34:06Z Article http://purl.org/eprint/type/JournalArticle 2469-9950 2469-9969 https://hdl.handle.net/1721.1/125036 Zhang, Ya-Hui, et al. “Landau Level Degeneracy in Twisted Bilayer Graphene: Role of Symmetry Breaking.” Physical Review B 100, 12 (September 2019): 125104. © 2019 American Physical Society en http://dx.doi.org/10.1103/PhysRevB.100.125104 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, Ya-Hui Po, Hoi Chun Todadri, Senthil Landau level degeneracy in twisted bilayer graphene: Role of symmetry breaking |
| title | Landau level degeneracy in twisted bilayer graphene: Role of symmetry breaking |
| title_full | Landau level degeneracy in twisted bilayer graphene: Role of symmetry breaking |
| title_fullStr | Landau level degeneracy in twisted bilayer graphene: Role of symmetry breaking |
| title_full_unstemmed | Landau level degeneracy in twisted bilayer graphene: Role of symmetry breaking |
| title_short | Landau level degeneracy in twisted bilayer graphene: Role of symmetry breaking |
| title_sort | landau level degeneracy in twisted bilayer graphene role of symmetry breaking |
| url | https://hdl.handle.net/1721.1/125036 |
| work_keys_str_mv | AT zhangyahui landauleveldegeneracyintwistedbilayergrapheneroleofsymmetrybreaking AT pohoichun landauleveldegeneracyintwistedbilayergrapheneroleofsymmetrybreaking AT todadrisenthil landauleveldegeneracyintwistedbilayergrapheneroleofsymmetrybreaking |