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Nature of the Correlated Insulator States in Twisted Bilayer Graphene.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Xie, Ming Donald, Allan H. Mac |
| Copyright Year | 2020 |
| Abstract | We use self-consistent Hartree-Fock calculations performed in the full π-band Hilbert space to assess the nature of the recently discovered correlated insulator states in magic-angle twisted bilayer graphene (TBG). We find that gaps between the flat conduction and valence bands open at neutrality over a wide range of twist angles, sometimes without breaking the system's valley projected C_{2}T symmetry. Broken spin-valley flavor symmetries then enable gapped states to form not only at neutrality, but also at total moiré band filling n=±p/4 with integer p=1, 2, 3, when the twist angle is close to the magic value at which the flat bands are most narrow. Because the magic-angle flat band quasiparticles are isolated from remote band quasiparticles only for effective dielectric constants larger than ∼20, the gapped states do not necessarily break C_{2}T symmetry and as a consequence the insulating states at n=±1/4 and n=±3/4 need not exhibit a quantized anomalous Hall effect. |
| Starting Page | 097601 |
| Ending Page | 097601 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| DOI | 10.1103/PhysRevLett.124.097601 |
| Alternate Webpage(s) | https://arxiv.org/pdf/1812.04213v2.pdf |
| PubMed reference number | 32202880 |
| Alternate Webpage(s) | https://doi.org/10.1103/PhysRevLett.124.097601 |
| Journal | Medline |
| Volume Number | 124 |
| Issue Number | 9 |
| Journal | Physical review letters |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
