Symmetry of electron bands in graphene: (nearly) free electron vs. tight-binding

Abstract

We present the symmetry labelling of all electron bands in graphene obtained by combining numerical band calculations and analytical analysis based on group theory. The latter was performed both in the framework of the (nearly) free electron model, or in the framework of the tight-binding model. The predictions about relative positions of the bands which can be made on the basis of each of the models just using the group theory (and additional simple qualitative arguments, if necessary) are complimentary.