Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 36: Posters: Bio/organic Molecules on Surfaces, Graphene, Solid/liquid interfaces, Metal Substrates, Electronic Structure Theory
O 36.87: Poster
Dienstag, 1. April 2014, 18:30–22:00, P1
Electron-phonon self-energy in the KKR formalism — •Carsten Eberhard Mahr, Marcel Giar, and Christian Heiliger — Justus-Liebig-Universität, Gießen, Germany
Electron-phonon coupling is one of the main incoherent inelastic scattering mechanisms in a wide variety of crystalline material systems at room temperature. Therefore, it is necessary to incorporate those effects in any realistic calculation of thermoelectric properties. We do so by extending our Korringa-Kohn-Rostocker (KKR) Green’s function formalism code.
Instead of including the electron-phonon coupling in the Kohn-Sham Hamiltonian via an adjusted effective potential Veff, we calculate the Green’s function of the ’free’ system (i.e., free of electron-phonon coupling) and employ Dyson’s equation G = Gfree + Gfree Σe-ph G to obtain the dressed Green’s function.
The self-energy Σe-ph is calculated using Keldysh NEGF formalism, which lends itself to a perturbative diagrammatic approach. Within this method it can be shown – ignoring any terms represented by disconnected Feynman diagrams – that at least so-called First Born Approximation is recovered.