Regensburg 2004 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 17: Postersitzung II: Transport, Quantenkoh
ärenz, Quantenflüssigkeiten

TT 17.7: Poster

Dienstag, 9. März 2004, 14:30–19:00, Poster A

Computersimulations of electronic charge transport in nanowires — •Markus Dreher and Peter Nielaba — Lehrstuhl für Theoretische Physik, Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, collaboration with Jan Heurich and Carlos Cuevas (Universität Karlsruhe)

With a molecular dynamic simulation we calculated the structure of gold nanocontacts which were pulled apart [1]. In order to prevent heating up the system during the stretching process we established a Nosé-Hoover thermostat. The gold atoms are interacting via an effective-medium-theory-potential incorporating many body effects [2]. The formation of single atom chains was observed.

In cooperation with Heurich and Cuevas, who developed -by using a tight-binding-model and Green function techniques- a program for the current through a nanocontact, conductivity curves (in different channels) have been determined and are in good agreement with the experimental data [1].

The conductance is not totally determined by the atoms of the constriction, but also by atom rearrangements in the vicinity of the constriction.

[1] M. Dreher, Diplomarbeit, Konstanz, 2002

[2] K. Jacobsen et al., A semi-empirical effective medium theory for metals and alloys, Surface Science, 366, 394 (1996)