Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 49: Frontiers of Electronic Structure Theory: Charge and Spin Dynamics (jointly with O, HL)
TT 49.3: Vortrag
Dienstag, 17. März 2015, 14:45–15:00, MA 004
Transfering spin into an extended π-orbital of a large molecule – ab-initio study of Au-PTCDA:Au(111) — •T. Deilmann1, T. Esat2, B. Lechtenberg3, P. Krüger1, C. Wagner2, R. Temirov2, F.B. Anders3, F.S. Tautz2, and M. Rohlfing1 — 1Institut für Festkörpertheorie, Universität Münster, Germany — 2Peter Grünberg Institute (PGI-3), FZ Jülich, Germany — 3Lehrstuhl für Theoretische Physik II, TU Dortmund, Germany
The combination of an organic molecule with an unpaired spin offers a large variety of interplay between spins and orbitals, with high sensitivity to structural and environmental details. Recently, a single Au atom on a PTCDA monolayer physisorbed on Au(111) has been investigated experimentally; it exhibits a Kondo peak in the STS spectrum.
In this talk we discuss ab-initio mean-field electronic spectra (which will then serve as input data for a subsequent NRG calculation to describe the Kondo effect). Based on ab-initio structural data (in agreement with observed STM images) we evaluate the electronic spectra by many-body perturbation theory within the GW approximation, as well as, a simplified LDA+GdW approach [1]. For gas-phase PTCDA and Au-PTCDA, both methods agree well with one another and with available measurements. For Au-PTCDA on Au(111), a full GW calculation is too expensive due to the substrate. LDA+GdW, on the other hand, fully allows to incorporate the substrate polarizability in the self energy inside the molecule and leads to good agreement with the experimental data.
[1] M. Rohlfing, Phys. Rev. B 82, 205127 (2010).