Ab initio Beschreibung der elektronischen Struktur und der Transporteigenschaften von metallischen Nanodrähten

Ab initio calculations of the electronic structure of freestanding Cu and Na nanowires with a diameter of few atoms are presented. The calculations are based on density functional theory in local density approximation using a Screened Korringa-Kohn-Rostoker-Green's function method. The method was extended for the description of quasi-onedimensional systems. Translational invariance in direction of the wire is assumed. The dependence of the bandstructure and the density of states from thickness and shape of the cross-section is discussed. The quantum confinement of the eigenstates is analysed. By comparing the results of the Na and Cu wires, the influence of the d-electrons is shown. Based on the Landauer theory of transport the conductance is obtained within a Green's function formalism. The numerical description of the conductance is tested for ideal translationally invariant Na and Cu wires. The influence of substitutional transition metal impurities on the electronic structure and the conductance of the 2x2 Cu wire is studied. A spin-dependent discussion is given for magnetic impurities.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Technische Universität Dresden

Year

2002

Author dc:creator

• Opitz, Jörg

Contributors dc:contributor

• Mertig, Ingrid
• Dederichs, P.H.
• Becker, Klaus

• Dichtefunktionaltheorie
• KKR
• Nanodraht
• Nanodrähte
• Transporteigenschaften
• ab initio
• elektronische Sruktur
• screened KKR
• nanotube
• nanowire