NONLINEAR SCREENING AND METALLIC ISLANDS CREATED BY DEFECTS OF DENSITY WAVES IN QUASI-ONE-DIMENSIONAL CONDUCTORS

We study the shape and the energy of 2 pi phase solitons, i.e., vacancies or interstitials of the electronic crystal formed by the density wave (DW), and the distortion of the DW induced by impurities. We show that at low temperatures nonlinear screening by electronic excitations strongly modifies the characteristic spatial and energy scales of phase distortions in DW conductors, resulting in the formation of metallic regions at the soliton center and around the impurities.