Localized description of band structure effects on Li atom interaction with graphene

MARCELO A. ROMERO; A. IGLESIAS-GARCÍA; E. C. GOLDBERG

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Año: 2011 vol. 83 p. 125411 - 125421

1098-0121

We study theoretically the localized aspects of the interaction between an Li atom and graphene. To this end, we use an ab initio calculation of the Hamiltonian terms within the Anderson model that allows us to take into account the chemical properties of Li and C atoms and the two-dimensional band structure of graphene. In this way, physical magnitudes of interest such as the hybridization function, the adatom spectral density and valence occupation are calculated. We find that the interference between the adatom neighboring sites together with the pronounced energy gap around the Γ point lead to negligible hybridization widths in a wide range of energies and are practically not dependent on the adsorption site. Consequently, this very weak coupling regime makes possible a local magnetic moment formation. Moreover, the strong suppression of the atom level broadening allows for an explanation of the unexpected neutralization measured at low energies in experiments of Li+ scattering by a highly oriented pyrolytic graphite surface.