ABSTRACT
When a system such as an electron device is driven far from equilibrium by the application of an external voltage, both coherent and incoherent processes will generally occur within the device. Coherent processes include tunneling and ballistic transport, and incoherent processes include dissipative scattering via phonons. The chapter explains the mathematical physics formulation of the Green’s function method. The solution of the Green’s function problem in principle is very difficult. The principal difficulty arises through the coupling of the quantum mechanical states to their environment and the filling of the states through contact regions and scattering interactions with the environment. The self-energy contributions from all scattering mechanisms included in the model are evaluated by employing the self-consistent Max Born approximation. The simulation of the semiclassical charge and the associated electrostatic potential is of course straightforward in equilibrium.
