Berlin 2018 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 21: Poster I

MA 21.50: Poster

Dienstag, 13. März 2018, 09:30–13:00, Poster A

Implementation of a self-consistent NEQ scheme in the KKR formalism — •Alexander Fabian, Michael Czerner, and Christian Heiliger — Institut für theoretische Physik, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 16, 35392 Gießen

Todays need for even more efficient and faster nano sized devices requires a decent understanding of the behavior of nanostructured materials under applied fields. However, most common approaches rely on the equilibrium properties of the material and use approximations to describe the non-equilibrium behavior. Since crucial assumptions have to be made, these descriptions do not always describe all of the properties correctly and one needs an exact description to calculate non-equilibrium properties. The Keldysh formalism can be used to describe the non-equilibirum properties within the framework of an ab initio theory. We implemented a self-consistent scheme in our multiscattering DFT code based on the KKR method. To calculate non-equilibrium properties, we use a steady state Keldysh formalism with non-equilibrium Green’s functions. The electronic density is calculated by splitting the energy contour in two parts according to the applied voltage. In the first part, the density is calculated with equilibrium tools while the second part is calculated with the actual Keldysh formalism. Summing the two parts the resulting density is used to solve the system self-consistently in the non-equilibrium steady state. Charge displacement due to the applied voltage and the behavior of the voltage in the underlying system are extracted from the self-consistent values.