Ab initio calculations of transport properties of single molecules: fundamental aspects and applications


Speaker: F. Evers



Predicting the transport characteristics of single molecules is one of the most daunting challenges in the theory of condensed matter systems. The crux of the matter is that two difficult computational complications exist – the genuine molecular many body problem and the thermodynamic limit of transport physics --  each of which by itself is amenable to  established  methods of many body physics, but the combined problems are not.

The first part of the  talk shall explain how this dilemma is dealt with in the  ``standard approach'', what are the pitfalls of the method and what boundary conditions should be met by improved approaches.

The second part of the talk will report about  methodological progress, which exploits  the fact that self energies can be implemented by certain absorbing boundary conditions. The procedure is very general and may be used in simulations of (effectively) noninteracting systems. The same principle carries over also to simulations of  interacting  many body systems. Several applications will be discussed.