A first-principles theory of Coulomb impurities on doped graphene: Application to calcium adatoms

Fabiano Corsetti, Arash A. Mostofi, Johannes Lischner

Published 2016-09-14Version 1

We investigate the electronic structure of doped graphene with a single adsorbed calcium (Ca) atom using a first-principles multiscale approach that combines linear-scaling density-functional theory, continuum Thomas-Fermi theory and large-scale tight-binding simulations. This approach accurately describes both the charge transfer between the adatom and graphene substrate and the long-range screening response of doped graphene to the Coulomb impurity. We show that 1.6 electrons are transferred from Ca to graphene, and analyze the effects of non-linearity, intraband and interband transitions and the exchange-correlation potential on the graphene response.