Doping dependence of low-energy band dispersions and magnetic properties of twisted bilayer graphene

Magic-angle twisted bilayer graphene (TBG) has drawn great attention for its correlated electronic phases appearing at different doping concentrations. To understand such phases, low-energy band dispersions need to be calculated accurately as a function of doping. However, the large number of atoms in the moiré supercell has limited theoretical calculations of doping effects on electronic and magnetic properties. Here, we present an efficient method to calculate electronic and magnetic properties of electron- and hole-doped TBGs based on results of density functional theory calculations of undoped TBG. With this method, we investigate doping and temperature dependences of electronic and magnetic properties of doped TBGs. We discuss effects of doping on electrostatic screening, low-energy band dispersions, and magnetization of TBG.