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...

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Bibliographic Details
Main Authors: Zhang, Ya-Hui (Author), Po, Hoi Chun (Author), Todadri, Senthil (Author)
Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor)
Format: Article
Language:English
Published: American Physical Society, 2020-05-06T13:47:39Z.
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Online Access:Get fulltext
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042 |a dc 
100 1 0 |a Zhang, Ya-Hui  |e author 
100 1 0 |a Massachusetts Institute of Technology. Department of Physics  |e contributor 
700 1 0 |a Po, Hoi Chun  |e author 
700 1 0 |a Todadri, Senthil  |e author 
245 0 0 |a Landau level degeneracy in twisted bilayer graphene: Role of symmetry breaking 
260 |b American Physical Society,   |c 2020-05-06T13:47:39Z. 
856 |z Get fulltext  |u https://hdl.handle.net/1721.1/125036 
520 |a 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. 
520 |a United States. Department of Energy (Grant DE-SC0008739) 
546 |a en 
655 7 |a Article 
773 |t Physical Review B