Angle-Resolved Photoemission Spectroscopy of Graphene, Graphite, and Related Compounds

High-resolution angle-resolved photoemission spectroscopy (ARPES) studies on carbon-based materials, such as graphene, graphite, and graphite intercalation compounds (GICs), are presented. We briefly review the basic principle of ARPES technique as well as the recent development of experimental apparatus, and then focus on the electronic structure in the vicinity of the Fermi level responsible for novel physical properties. We discuss the energy band structure and the Fermi surface of graphene and graphite in terms of the many-body interaction, the edge-localized states, and the Dirac-fermion-like behavior. We also explain the first direct ARPES observation of the interlayer band and the superconducting gap in a high-T_c GIC, C₆Ca.