Regensburg 2013 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 58: Poster Session Transport & Matter at Low Temperature

TT 58.19: Poster

Donnerstag, 14. März 2013, 15:00–19:00, Poster D

Electronic structure and transport properties of crossed carbon nanotubes — •Fabian Teichert¹, Andreas Zienert¹, and Jörg Schuster² — ¹Center for Microtechnologies, Chemnitz University of Technology, Chemnitz, Germany — ²Fraunhofer Institute for Electronic Nano Systems, Chemnitz, Germany

According to their geometric structure carbon nanotubes (CNT) have different electronic properties. The metallic ones could be used for interconnects in future microelectronic devices. During experimental preparation CNTs can not be placed isolated. They get curved and form bundles. Therefore it is necessary to study the interaction of closely neighboring CNTs and its influence on the electronic and transport properties.

In the present work the attention is focused on a special geometry, where two (4,1)-CNTs (one curved and one linear) are aligned at a minimum distance of 3 Å. For this system electron densities, densities of states and transmission spectra are obtained from ab initio simulations. To get the current-voltage characteristic I(U), transmission spectra are calculated for non-zero voltages by the use of non-equilibrium Green’s function theory and integrated within the Landauer-Büttiker formalism. All calculations are performed for various angles α between the periodic axes of the two CNTs so that the influences of the crossing and curving effects could be extracted separately. The simulations show that the behavior of I(U) changes with increasing α. Furthermore, the reduction of the current with respect to a linear CNT is dominated by the crossing effect for small α and by the curving effect for large α.