Berlin 2008 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 18: Poster I : Bio Magn. (1-2); Mag.Imgaging (3-9); Magn. Semiconductors (10-16); Half Metals & Oxides (17-20); Coupl.Phenomena (21-27); Magn. Mat. (28-41); Micro & Nanostr. Magn. Materials (42-61); Micro Magn. (62-64); Surface Magnetism (65-70); Transport Phenomena (71-85)
MA 18.85: Poster
Dienstag, 26. Februar 2008, 15:15–18:30, Poster E
Bias dependence in mesoscopic systems using non-equilibrium Green’s functions — •Steven Walczak1, Christian Heiliger2,3, Michael Czerner1, and Ingrid Mertig1 — 1Department of Physics, Martin Luther University,D 06099 Halle, Germany — 2Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899-6202 — 3Maryland NanoCenter, University of Maryland, College Park, MD, 20742
The understanding of bias dependencies is a key issue in ballistic transport. In particular, the voltage drop within the scattering region depends strongly on the geometry of the system. For example in a tunnel junction one expects a simple linear voltage drop over the barrier but for atomic contacts, nanowires, or molecules the voltage drop is expected to be more complicated. To account for these systems we extend our implementation of the Keldysh formalism in the Korringa-Kohn-Rostoker Green’s function method [1]. This extension includes the self-consistent treatment of the system under applied bias using the non-equilibrium density between the chemical potentials of the left and the right lead. The voltage drop within the system is then the difference of the densities with and without an applied voltage. We compare ab initio results of voltage drops in different geometries. This work has been supported in part by the NIST-CNST/UMD-NanoCenter Cooperative Agreement.
[1] C. Heiliger, M. Czerner, B. Yavorsky, I. Mertig, M. Stiles, J. Appl. Phys. (in press), arXiv:0711.2082