Pseudo Dirac dispersion in Mn-intercalated graphene on SiC

The atomic and electronic structures of bulk C6Mn, bulk C8Mn, and Mn-intercalated graphene on SiC(0 0 0 1) and SiC ( 0 0 0 1 ¯ ) are investigated by density functional theory. We find for both configurations of Mn-intercalated graphene a nonmagnetic state, in agreement with the experimental situation for SiC(0 0 0 1), and explain this property. The electronic structures around the Fermi energy are dominated by Dirac-like cones at energies consistent with data from angular resolved photoelectron spectroscopy [Gao et al., ACS Nano. 6 (2012) 6562]. However, our results demonstrate that the corresponding states trace back to hybridized Mn d orbitals, and not to the graphene.