Nonlinear calculation of the stopping power of a two-dimensional electron gas for heavy particles

We present a nonlinear calculation of the stopping power of a two-dimensional electron gas in its ground state at metallic and overmetallic densities (1<rs<10) for slow heavy repulsive intruders (antiprotons). We employ a scattering (kinetic) approach with the effective scattering potential coming from the profile equation of the Sjölander-Stott theory. A similar calculation in three dimensions shows excellent agreement with the density-functional theory results. In two dimensions, we obtain a stopping power which falls in between the bare Coulomb and linear screening potential treatments.