Regensburg 2013 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 60: Graphene - Theory (jointly with DS, HL, MA, and O)
TT 60.2: Talk
Thursday, March 14, 2013, 15:15–15:30, H17
Generalized Hubbard models for two dimensional hybrid materials — •M. Rösner1, E. Sasioglu2, C. Friedrich2, S. Blügel2, A. I. Lichtenstein3, M. I. Katsnelson4, and T. O. Wehling1 — 1Institut für Theoretische Physik, Universität Bremen, D-28359 Bremen, Germany — 2Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany — 31. Institut für Theoretische Physik, Universität Hamburg, D-20355 Hamburg, Germany — 4Radboud University Nijmegen, Institute for Molecules and Materials, NL-6525 AJ Nijmegen, The Netherlands
We present effective generalized Hubbard models for the description of novel two dimensional materials. The local and non-local partially screened Coulomb interaction as well as hopping integrals are calculated from first principles for silicene and graphene on a metallic substrate. We consider interactions up to the 6th nearest neighbor in real space and investigate the long range behavior of the dielectric function in k-space. We compare the resulting silicene Hubbard model to the corresponding model for pure graphene. Thereby we find values of U/t ≈ 4.0 eV for the on-site and V/t ≈ 2.4 eV for the nearest neighbor partially screened Coulomb interaction in silicene, which are slightly bigger than in freestanding graphene. We further show that the ratio of the local to the non-local Coulomb interaction can be controlled by a metallic substrate, which efficiently screens non-local Coulomb terms.