Magic-angle Twisted Bilayer Graphene: Magnetoplasmons

Magic-angle twisted bilayer graphene (MATBLG) is known for its exotic physical properties arising from its unique flat bands. However, the engineering of these properties through external fields remains largely unexplored. In this study, we demonstrate that MATBLG exhibits a distinctive magnetoplasmon dispersion when subjected to an external magnetic field, which can be significantly altered by transferred momentum and charge doping. Over a broad range of transferred momentum, we identify prominent single magnetoplasmon and horizontal single-particle excitation modes near charge neutrality. We provide a detailed analysis of these unique features, linking them to electronic excitations of Landau levels quantized from the flat bands and the effects of Landau damping. Furthermore, charge doping introduces intriguing multiple strong-weight magnetoplasmons. These characteristics position MATBLG as a promising candidate for plasmonic devices and technological applications.