Field theoretical approach for describing local properties in disordered systems.

Field theoretical approaches have in the past been used extensively to study general properties of disordered electronic systems. However, these models tend to be very general and therefore lack material dependent properties. In addition, these models often contain assumptions that become increasingly poor if one desires to study local properties of the system. It is true that in the macroscopic regime the effects of these kinds of details do not affect the scaling behaviour of the system, however, if one desires to study properties away from the critical points, including these details become crucial. Furthermore, understanding local properties has become increasingly important as they govern device-specific behavior and are now directly accessible through experimental techniques such as scanning tunneling microscopy (STM). In this work we construct a field theory in the language of prior established nonlinear sigma models to study local properties of a disordered 2DEG. The model incorporates material-dependent parameters that allow it to predict local properties of experimentally realizable disordered systems such as delta-doped layers.