title: Nonlinear screening in two-dimensional electron gases.
abstract: We have performed self-consistent calculations of the nonlinear screening of a point charge Z in a two-dimensional electron gas using a density functional theory method. We find that the screened potential for a Z=1 charge supports a bound state even in the high-density limit where one might expect perturbation theory to apply. To explain this behavior, we prove a theorem to show that the results of linear response theory are in fact correct even though bound states exist.
authors.affiliation: Department of Physics, Queen's University, Kingston, Ontario, Canada K7L 3N6.
authors.forename: E
authors.initials: E
authors.lastname: Zaremba
authors.forename: I
authors.initials: I
authors.lastname: Nagy
authors.forename: P M
authors.initials: PM
authors.lastname: Echenique