Moment Models: Microscopic to Macroscopic

In this chapter, we shall present alternative models to that of drift-diffusion. More precisely, the models developed here are refinements, for which drift-diffusion is a limiting case. The two which we select are the classical hydrodynamic model, and a class of energy transport models. A quantum transport variant of the hydrodynamic model is briefly discussed at the conclusion of the chapter. For the reader who wishes to pursue these topics in greater detail, a special issue of VLSI DESIGN, edited by the author, has appeared (vol. 3, no. 2, 1995).