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TT: Fachverband Tiefe Temperaturen
TT 21: TR: Nanoelectronics III - Molecular Electronics 2
TT 21.1: Vortrag
Dienstag, 15. März 2011, 10:30–10:45, HSZ 301
Spatio-Temporal description of Quantum Transport — •Björn Oetzel1,2, Friedhelm Bechstedt1,2, and Karsten Hannewald1,2 — 1Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany — 2European Theoretical Spectroscopy Facility, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
We present a numerical method for the calculation of time-dependent transport properties of non-periodic systems connected to electron reservoirs. The approach is based on the solution of the time-dependent Schrödinger equation combined with the emitting boundary conditions using plane waves as modeling of the leads.
Using the approach we are able to simulate the temporal evolution of wave packets through potential barriers. Within the quasi-stationary limit the method can be associated with the Landauer Formalism. Transmission functions are calculated directly from the transmitted and reflected currents for the insertion of a single plane wave. Beyond the calculation of transmission functions the approach is also capable of field-dependent transport properties such as current voltage characteristics. Those can be calculated independently of the transmission functions including by direct treatment of time-dependent potentials and electrical fields, in contrast to the Landauer approach. The success of the method is demonstrated by 1D-model calculations for single and double barriers including modifications due to applied electrical fields.