Use of the scattering matrix for device simulations

The use of the quantum mechanical scattering matrix is a time proven method for determining the transport probability for an electron wave in a nanostructure. When coupled with the Landauer formalism, it provides a valuable approach for simulation of semiconductor devices. Here, we discuss a numerically stable method to solve this transmission problem in a recursive manner. It is easily extended to dissipative and far from equilibrium situations. We also discuss the use of scattering matrices in photo excitation of nanostructures.