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arXiv · 1806.05990

Electrostatic effects, band distortions and superconductivity in twisted graphene bilayers

Francisco Guinea·Niels R. Walet
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Abstract

Bilayer graphene twisted by a small angle shows a significant charge modulation away from neutrality, as the charge in the narrow bands near the Dirac point is mostly localized in the regions of the Moir\'e pattern with $AA$ stacking. The resulting electrostatic potential gives rise to the dominant contribution to the electron-electron interaction within this low energy band, which becomes significantly distorted. The changes in the band structure are described by new local interactions, and lead to an assisted electron-hopping process. These couplings favor superconductivity at certain fillings.

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Francisco Guinea, Niels R. Walet. 2018-06-15. Electrostatic effects, band distortions and superconductivity in twisted graphene bilayers. https://doi.org/10.1073/pnas.1810947115

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