Abstract
We propose a lattice-scale two-band generalized Hubbard model as a caricature of the electronic structure of twisted bilayer graphene. Various possible broken-symmetry phases can arise, including a nematic phase (which is a form of orbital ferromagnet) and an orbital-triplet spin-singlet superconducting phase. Concerning the mechanism of superconductivity, we propose an analogy with superconductivity in alkali-doped in which a violation of Hund's first rule plays a central role.
- Received 8 May 2018
DOI:https://doi.org/10.1103/PhysRevB.98.075154
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