EFFECTIVE SIZE OF SCATTERING CENTERS IN A 2-DIMENSIONAL ELECTRON-GAS

The screening behavior of a two-dimensional electron gas (2DEG) subjected to a periodic lattice of scattering centers or "antidots" is investigated. We have obtained an exact solution for the nonlinear screening problem of a 2DEG containing a single antidot and we have worked out a Monte Carlo simulation method to solve the case of a periodic antidot lattice. We also provide general theoretical predictions concerning the depletion phenomenon in this system. The shrinkage of the effective antidot size with increasing carrier density of decreasing periodicity of the lattice has been calculated and compared with experimental results.