Dresden 2014 – wissenschaftliches Programm
O 19.7: Vortrag
Montag, 31. März 2014, 17:30–17:45, WIL C107
From two to three dimensions: The effect on the Coulomb interaction by increasing the dimensionality in layered materials — •M. Rösner1, E. Sasioglu2, C. Friedrich2, S. Blügel2, A.I. Lichtenstein3, M.I. Katsnelson4, and T.O. Wehling1 — 1Institut für Theoretische Physik and Bremen Center for Computational Materials Science, Universität Bremen, Bremen, Germany — 2Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, Jülich, Germany — 3I. Institut für Theoretische Physik, Universität Hamburg, Hamburg, Germany — 4Radboud University Nijmegen, Institute for Molecules and Materials, AJ Nijmegen, The Netherlands
We study the Coulomb repulsion and the dielectric screening in mono-, bi- and tetralayer graphene as well as in graphite. We discuss the transition from 2D systems to the bulk structure in layered materials with regard to the (non) local Coulomb interactions. Therefore, we use ab initio constrained random phase (cRPA) calculations to get reliable data in a first step. By tailoring the resulting Coulomb interaction in classical electrostatic models afterwards, we find the following: In addition to the effective height of each layer especially the direction dependence and the non-locality of the dielectric function are the keys to understand the screening effects in these structures. Thereby, we discuss models to estimate the Coulomb interaction of the 2D systems by using exclusively the bulk data as input. We apply these rules to calculate the Coulomb interaction in graphene on iridium and find a very good agreement with ab initio data.