Quantum electrical capacitance in epitaxial graphene

Abstract

We used a simple model to investigate the quantum electrical capacitance of epitaxial graphene, which changes abruptly at the boundary between permitted and forbidden energies. We studied a case of a size-quantized substrate. We obtained energy, temperature, and concentration dependences. Some of the results are in satisfactory agreement with the available experimental results. We discuss the renormalization of the Fermi velocity of graphene electrons by the substrate.