Pith. sign in

REVIEW 4 cited by

On the nature of the correlated insulator states in twisted bilayer graphene

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 1812.04213 v2 pith:CSECQHM4 submitted 2018-12-11 cond-mat.str-el

classification cond-mat.str-el
keywords statesbandflatbandsbilayercorrelatedgappedgraphene
verification ladder T0 review T1 audit T2 compute T3 formal
0 comments
abstract

We use self-consistent Hartree-Fock calculations performed in the full $\pi$-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 ${\cal C}_{2}{\cal T}$ symmetry. Broken spin/valley flavor symmetries then enable gapped states to form not only at neutrality, but also at total moir\'e band filling $n = \pm p/4$ 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 $ \sim 20$, the gapped states do not necessarily break \CT symmetry and as a consequence the insulating states at $n = \pm 1/4$ and $n = \pm 3/4$ need not exhibit a quantized anomalous Hall effect.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 4 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Superconductivity from collective excitations in magic angle twisted bilayer graphene

    cond-mat.mes-hall 2019-09 conditional novelty 6.0 of 10

    Collective electronic modes can mediate Cooper pairing in magic-angle twisted bilayer graphene, producing an asymmetric superconducting dome around 10^12 electrons/cm^2 with critical temperatures near a few kelvin.

  2. Attractive electron-electron interactions from internal screening in magic angle twisted bilayer graphene

    cond-mat.str-el 2019-09 conditional novelty 6.0 of 10

    Using RPA and cRPA, the authors find twist-angle-dependent screening in magic-angle twisted bilayer graphene, including real-space attractive regions in the RPA interaction and strongly reduced Hubbard parameters.

  3. Giant Orbital Magneto-electric effect and Current-driven Magnetization Switching in Twisted Bilayer Graphene

    cond-mat.mes-hall 2019-08 reject novelty 6.0 of 10

    A small current in strained, hBN-aligned twisted bilayer graphene is predicted to generate a large out-of-plane orbital magnetization and to switch the ferromagnetic state near 3/4 filling.

  4. Collective Excitations of Quantum Anomalous Hall Ferromagnets in Twisted Bilayer Graphene

    cond-mat.mes-hall 2019-08 conditional novelty 6.0 of 10

    A microscopic calculation shows that the quantum anomalous Hall ferromagnet in twisted bilayer graphene is stable against spin and valley magnons, and that valley wave fluctuations limit the ordering temperature.

Pith tools