  We propose that the experimentally observed resistivity upturn of cuprates at
low temperatures may be explained by properly accounting for the effects of
disorder in a strongly correlated metallic host. Within a calculation of the DC
conductivity using real-space diagonalization of a Hubbard model treated in an
inhomogeneous unrestricted Hartree-Fock approximation, we find that
correlations induce magnetic droplets around impurities, and give rise to
additional magnetic scattering which causes the resistivity upturn. A pseudogap
in the density of states is shown to enhance both the disorder-induced magnetic
state and the resistivity upturns.
