Nonlinear screening in two-dimensional electron gases.
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.
Zaremba
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Department of Physics, Queen's University, Kingston, Ontario, Canada K7L 3N6.
Nagy
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Echenique
P M
PM