14.1.2014, 17:00 Jungiusstr. 11, Hörsaal AP | SFB 668 - Kolloquium **Dr. P. Hansmann (Ecole Polytechnique):**
## Long-Range Coulomb Interactions in Adatom Systems on the Si(111) SurfaceSystems of adatoms on semiconductor surfaces display competing ground states and exotic spectral properties typical of two-dimensional correlated electron materials which are dominated by a complex interplay of spin and charge degrees of freedom. We report a fully ab initio derivation of low-energy Hamiltonians for the adatom systems Si(111):X (with X=Sn, Si,
C, Pb) that we solve within self-consistently combined GW and dynamical mean-field theory. Calculated photoemission spectra are in agreement with available experimental data. We rationalize experimentally observed trends
from Mott physics toward charge ordering along the series as resulting from substantial long-range interactions. |