Influence of Twist-Angle and Concentration Disorder on the Density of Electronic States of Twisted Graphene

In this paper, we present an approach that makes it possible to describe, from unified physical considerations, the influence of rotation-angle and concentration disorder on the density of electronic states of two-layer twisted graphene. The electron relaxation time and the density of electronic states near the Fermi level are calculated by considering the multiple elastic scattering of electrons by impurities and structural inhomogeneities of the short-range order type. An analysis is presented of the change in the contributions to the density of electronic states from electron scattering on foreign atoms with variations in the defectiveness of the structure, impurity concentration, temperature, and the external electric field magnitude. It is shown that the formation of short-range order areas by foreign atoms in the first coordination sphere relative to the surface of the material can lead to the opening of a gap in the density of electronic states of twisted graphene. Point defects and short-range order regions formed by foreign atoms in the second coordination sphere lead to metallization of twisted graphene.