ELECTRONIC DIELECTRIC RESPONSE OF COMPOSITE-MATERIALS - APPLICATION TO 2-DIMENSIONAL ELECTRONIC TRANSPORT

We derive the formal expression for the dielectric response of composite semiconducting materials and then show that the inverse dielectric function can be approximately deduced in the particular case of a two-dimensional electron gas (2DEG) embedded between two media. In given situations, these surrounding media contribute noticeably to the non-local dielectric response. This allows us to propose a general formulation for the actual scattering potentials acting against the motion of the 2DEG in transport experiments. The improvement brought about by our model is pointed out in the particular case of ionized impurity scattering.