Spatial conductivity modulation at metallic point defects

Electromigration theories have brought increasing recognition that lattice inhomogeneities in metals produce spatial variations in current flow and in the associated transport field. It is shown, through a semiclassical one-dimensional model, that the spatial variations of carrier density near a lattice defect can produce strong local variations in the field required for current flow. This particular source of field inhomogeneity does not seem to have been recognized in earlier discussions.