[Zurück]

K. Palotás, B. Lazarovits, L. Szunyogh, P. Weinberger:
"Electric properties of nanostructures";
in: "Handbook of Theoretical and Computational Nanotechnology", M. Rieth, W. Schommers (Hrg.); American Scientific Publishers, Los Angeles, 2006, ISBN: 1-58883-042-x, S. 364 - 408.

This contribution is devoted to the theoretical description of the electric properties of nanos-
tructured matter, in particular to structures nanoscaled in two dimensions, namely supported
clusters of atoms such as finite chains of atoms embedded in the surface of a metallic sub-
strate or atomic-sized contacts. Because this description is based on a "real space" represen-
tation of the so-called Kubo-Greenwood equation, it was felt necessary to give first a proper
account of the theoretical background of linear response theory in terms of electric fields.
For this reason Section 2 deals quite generally with currently available transport theories.
In putting the Kubo-Greenwood equation into a computationally accessible scheme the use
of density functional theory and multiple scattering approaches is required. Therefore only
after having summarized very shortly the main quantities in a Korringa-Kohn-Rostoker-type
realization of multiple scattering (Section 3), practical expressions for evaluating electric
properties of nanostructures are introduced (Section 4). Clearly enough the numerical accu-
racy of such approaches have to be documented before any kind of application to nanosized
matter can be given. Unfortunately this kind of numerical "test" leads back to bulk materials,
for which the electric properties are well documented, both experimentally and theoreti-
cally. However, only the "tests" discussed in Section 5 provide the necessary confidence
for the theoretical results presented in Sections 6 and 7 for finite wires and atomic-sized
contacts.
Not dealt with in this contributions are systems nanosized only in one dimension such as
spin valves or other heterojunctions, as a review of such systems-also based on a Green´s
function realization of the Kubo-Greenwood equation-only appeared rather recently [1]
that discusses in quite some length, for example, properties of the giant magnetoresistance
(GMR).