The goal of the proposed project is to achieve a better understanding of the way in which interaction influences transport properties of small structures coupled to left and right leads. To this end we concetrate on two aspects: (1) the interplay of interaction and interference for structures with degenerate levels at the Fermi surface. (2) On the role of interaction during transient times, i.e. the dynamics between switching on the transport voltage and the reach of a steady state (if it exists). To this end we apply the density matrix renormalization group method (DMRG) which allows us to study the time evolution of interacting, low-dimensional quantum systems with high accuracy. These simulations are supplemented by a direct calculation of correlation function in frequency domain to obtain a better understanding. While these questions are scientifically rewarding by themselves, we would also like to extract exact static and time-dependent exchange correlation potentials from our simulations to achieve a better understanding of the description of transport phenomena within (time-dependent) density and current-density functional theories (DFT). We believe that such an understanding is an undispensable prerequisite for the development of a Molecular Electronics.
