Nach positiver Absolvierung der Lehrveranstaltung sind Studierende in der Lage die in der Lehrveranstaltung angebotenen Lehrinhalte zu erfassen und selbstständig zu interpretieren sowie sämtliche Lehrinhalte auch aktiv weiterzugeben.

Electronic structure calculations of topical materials such as - thermoelectrics - novel superconductors - heavy Fermion systems - strongly correlated heterostructures Methods: local denisty approximation (LDA) dynamical mean field theory (DMFT) LDA+DMFT dynamical cluster approximation More detailed examples: Projektarbeit LDA+DMFT for thermoelelectrics The Seebeck process allows us to transfer excess waste heat into electrical energy. A broader technical application of this process might help to mitigate the world's energy problems. However, the low Seebeck coefficient of presently known materials results in a low efficiency of the process and hence prevents us from a technical realization on a larger scale. The aim of the Projektarbeit is to calculate Seebeck coeficients of materials with correlated electrons by means of the local density approximation (LDA) and/or dynamical mean field theory (DMFT), and ultimatively to find guiding principles for materials with extraordinarily large Seebeck coeficients. Projektarbeit Computational Materials Science The straight road to LDA+DMFT The aim of this Projektarbeit is a direct implementation of the LDA+DMFT approach for LDA basis sets of a mixed plane wave and local orbital chararacter, such as those in the two Vienna LDA program packages (Wien2K and VASP).

Interaktiver Kurs

The calculation of electronic properties of materials is an important task of solid state theory, albeit particularly difficult if electronic correlations are strong, for example in transition metals, their oxides and in f-electron systems. The standard approach to material calculations, the density functional theory in its local density approximation (LDA), incorporates electronic correlations only very rudimentarily and fails if the correlations are strong. Encouraged by the success of dynamical mean field theory (DMFT) in dealing with strongly correlated model Hamiltonians, physicists from the bandstructure and the many-body community have joined forces and developed a combined LDA+DMFT method recently. Depending on the strength of electronic correlations, this new approach yields a weakly correlated metal as in LDA, a strongly correlated metal, or a Mott insulator. By now, this approach is widely regarded as a breakthrough for electronic structure calculations of strongly correlated materials (see http://arxiv.org/abs/cond-mat/0511293).

Protokoll

Grundkenntnisse in Festkörperphysik