We study the density disturbance of a correlated 1D electron liquid in the
presence of a scatterer or a barrier. The 2k_F-periodic density profile away
from the barrier (Friedel oscillation) is computed for arbitrary
electron--electron interaction and arbitrary impurity strength. We find that in
presence of correlations, the Friedel oscillation decays slower than predicted
by Fermi liquid theory. In the case of a spinless Luttinger liquid
characterized by an interaction constant g<1, the asymptotic decay of the
Friedel oscillation is x^-g. For a weak scatterer, the decay is even slower at
small-to-intermediate distances from the impurity, with a crossover to the
asymptotic x^-g law.Comment: 26 pages, includes special style file and 7 eps-files, to appear in:
"Quantum Transport in Semiconductor Submicron Structures", edited by B.
Kramer, NATO-ASI Series E (Kluwer, Dordrecht, 1996
