Localization of π-electron density in twisted bilayer graphene

In bilayer graphene, mutual rotation of layers has strong effect on the electronic structure. We theoretically study the distribution of electron density in twisted bilayer graphene with the rotation angle of 21.8 degrees and find that regions with AA-like and AB-like stacking patterns separately contribute to the interlayer low-energy van Hove singularities. In order to investigate the peculiarities of interlayer coupling, the charge density map between the layers is examined. The presented results reveal localization of p-electrons between carbon atoms belonging to different graphene layers when they have AA-like stacking environment, while the interlayer coupling is stronger within AB-stacked regions. [GRAPHICS] Charge density map for bilayer graphene with a layer twist of 21.8 degrees(interlayer region). (C) 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim