Effects of electrostatic fields and charge doping on the linear bands in twisted graphene bilayers

摘要: A twisted graphene bilayer consists of two monolayers rotated by an angle $\ensuremath{\theta}$ with respect to each other. Theory predicts that charge-neutral bilayers display a drastic reduction their Fermi velocity ${v}_{F}$ for $0\ensuremath{\lesssim}\ensuremath{\theta}\ensuremath{\lesssim}{20}^{\ensuremath{\circ}}$ and $40\ensuremath{\lesssim}\ensuremath{\theta}\ensuremath{\lesssim}{60}^{\ensuremath{\circ}}$. In this paper we present evidence additional anisotropic in the presence external electrostatic fields. We also discuss quantitative detail renormalization other relevant bands vicinity $K$ point. Except rigid energy shift, fields doping metal atoms give rise similar band structure bilayers.