Dresden 2020 – scientific programme
The DPG Spring Meeting in Dresden had to be cancelled! Read more ...
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 24: Poster Session - Electronic-Structure Theory: General
O 24.2: Poster
Monday, March 16, 2020, 18:15–20:00, P1A
Complex contour integration in non-equilibrium Green’s function formalism — •Jonas Fey1, Michael Czerner1,2, and Christian Heiliger1,2 — 1Institut für theoretische Physik, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen — 2Zentrum für Materialforschung (LaMa), Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen
In a previous work we introduced a new method for calculating the electronic density as a partial step in a self-consistent algorithm using Green’s functions by calculating a non-equilibrium occupation function for complex-valued energies. In order to calculate the density in the non-equilibrium steady state Keldysh formalism, one needs a high amount of computational effort, since the integration is along the real energy axis. Going to the complex plane allows for less computational effort, but the non-equilibrium occupation function is needed. The calculation of this function worked well for a single step and indicated the possibility to make electronic structure calculations more efficient. The validity for a complete self-consistent calculation remains open. Therefore, we tested the method for different model systems simulating for example a potential barrier or a quantum dot. We investigated the correctness of our results as well as the convergence depending on the number of energy points. Furthermore, we studied analytic properties of the functions used which are crucial for the functionality of our method.