Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 35: Postersession Transport: Nanoelectronics, Quantum Coherence and Quantum Information, Fluctuations and Noise
TT 35.7: Poster
Mittwoch, 25. März 2009, 14:00–18:00, P1A
Transport properties of smooth and rough interfaces — •Mohamed Fadlallah1, Cosima Schuster1, and Udo Schwingenschlögl2 — 1Institut für Physik, Universität Augsburg, D-86135 Augsburg, Germany — 2ICCMP, Universidade de Brasilia, 70904-970 Brasila-DF, Brazil
The functionality of nanoscale devices depends crucially on the transport properties across the interfaces. As devices are reduced in size, interfaces dominate the transport. Nanocontacts hence were studied intensively over the last years and many approaches to calculate the transport were developed. Most are based on electronic structure calculations to obtain the material specific aspects. Nevertheless the properties of simple distorted interfaces are not well understood. Distortions may occur due to orientation mismatch, vacancy sites, buckling of the interface layer, or impurities. We discuss the equilibrium and non-equilibrium properties of distorted interfaces between simple metals (Au, Al) using the SMEAGOL code which combines density functional theory (DFT) and non-equilibrium Green's functions (NEGF) by using Landauer formula. The transmission coefficient is proportional to the density of states (DOS). Only in the case of a vacancy, we see a substantial reduction of the transmission coefficient near the Fermi level. Other kinds of distortion influence only the transmission at lower energies. With increasing voltage the transmission coefficient of the d-band decreases linearly, but stays constant near the Fermi level in the gold system. For Aluminum it is reduced over the whole energy range. This work was done in the collaboration with Dublin group of SMEAGOL.