Nonequilibrium Transport in Nanostructures

Andreas Wacker

Technische Universität Berlin, Germany

The electronic properties of semiconductor nanostructures are essentially determined by quantum effects, which determine the discrete nature of energy states, tunneling rates as well as optical transitions. Therefore a quantum transport theory is indispensable for the description of such structures (although some estimates can already be obtained from a semiclassical heuristics). Due to the small dimensions of semiconductor nanostructures even small bias voltages can drive such structures far from equilibirum. Nonequilibrium Green function techniques allow for a consistent description of these devices in particular for stationary states. I will give an outline of this theory and discuss its strength as well as limitations. Particular applications towards the transport through superlattices and quantum dots are given.