S-type Single Alkali-Adatom on Graphene

GARCÍA, EVELINA ANDREA; A. IGLESIAS GARCÍA; GOMEZ CARRILLO S; M. A. ROMERO

APPLIED SURFACE SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2018 vol. 452 p. 507 - 513

0169-4332

We present a theoretical study of the localized aspects of the alkali-metal atoms (Li, Na, K) interactingwith graphene. We use an ab-initio calculation of the Hamiltonian parameters where the chemical propertiesof the interacting atoms (alkali and C), and the extended features of the electronic band structure ofthe solid are considered. Adatoms with a s-type valence orbital where the electron repulsion (U) in theatom assumes a finite value are considered. Three possible configuration states are analyzed: zero, one(spin up or down), and two electrons in the valence state. We describe the surface-atom interaction byprojecting the Anderson Hamiltonian on the subspace of these atomic configurations, and introducedthe Green?s functions required to calculate the magnitudes of interest. Physical quantities of interest suchas hybridization function, the adatom spectral density and transferred charge are obtained. We find thatthe interaction of alkali-metal atoms with graphene involves several atoms of the solid due to the extensionof the s-type alkali atomic state and C atomic states. Charge is mostly transferred from the adatomtowards the graphene sheet.