Effect of Magnetic-Impurity Scattering in Disordered Two-Dimensional Square Lattices Around Half Filling

Weak-localization effect in the presence of magnetic impurities is studied in disordered two-dimensionaltight-hinding square lattices around half filling.Both the magnetic and nonmagnetic impurities are assumed to berandomly distributed on small fractions of the sites,while the nonmagnetic impurities have a strong potential yielding aunitary-limit scattering.We derive in details the expressions of diffusive π modes in the retarded-retarded(or advanced-advanced)channel,which result from the existence of particle-hole symmetry.The quantum interference correctionto the density of states is calculated.While the magnetic-impurity scattering suppresses the quantum correction fromπ-mode cooperon,it does not affect the contribution of π-mode diffuson.