The physical and chemical properties of ultra-small structures are mostly determined by their edges or borders. That's why they can be controlled and manipulated via their interfaces. This is true for all nano-objects, and this property will become more and more important with the progressing miniaturization, as, e.g. in micro-electronic circuits by use of ultra-small and ultra-fast chip architectures or in the design of new catalysts. The scientific importance of interfaces and of their relevance for applications was once more underlined by the Nobel prizes of the year 2007 both in physics and in chemistry (Grünberg, Fert and Ertl).
In this context, our group is interested mainly in the generation, characterization and manipulation of ultra-small structures on surfaces on the scale of a few nanometers down to single atoms, and in their fundamental physical properties. Structures like ordered arrays of atomic wires or noncontacts are generated by a combination of well-established concepts of surface science using self-orga-nization (bottom-up approach) and mesoscopic as well as macroscopic structuring (top-down ap-proach). We are thus able to study, e.g. the electronic and electric transport properties of objects in zero, one and two dimensions. Particularly exciting are questions how these properties are interconnected, how they depend on certain combinations of materials and on their morphology.
In order to answer these questions a variety of tools for their investigation are necessary, which should be both surface sensitive and simultaneously yield information on the atomic scale such as tunneling microscopy (STM) and electron diffraction (LEED), or various kinds of electron spectroscopy (UPS, XPS and EELS).
Current research covers the following topics: