Regensburg 2013 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 13: Topical Session: Quasicrystals & Complex Metallic Alloys III

MM 13.1: Vortrag

Montag, 11. März 2013, 15:45–16:00, H25

Dealing with the complexity of complex matter — •Peter Häussler — University of Technology, Institute of Physics, 09107 Chemnitz, Germany

Describing the structure of complex systems is difficult enough but, due to the huge unit cell and unknown decoration of the lattice sites, what often happens, calculating their properties is even worse. Understanding their structural evolution from e.g. the gaseous or liquid state and the reasons where structural peaks finally arise is far out of this range. One way, to reduce the tremendous number of parameters and hence to understand their structural development as well as the evolution of physical properties, is to give up a microscopic understanding based on a detailed description of all the individual atoms. We may even ask, is it really necessary to know all these details which we may, probably, never be able to get? Can we tread the complexity with reduced information? If we are able to find global subsystems, consisting of many species which are acting collectively, we would be able to reduce the tremendous number of independent parameters to a few only. If we are further able to describe with these parameters the major effects causing the atomic distances as well as main physical properties, we may have understood a lot. I will talk in this presentation on global effects of different subgroups of electrons. The combined s/p-electrons, the s-electrons alone, as well as the d-electrons, all have their own effects on structural features. Together with the structure they cause the metallic, insulating or semiconducting properties, are defining the atomic density and many more quantities.