Kondo Effect in Disordered Two-Dimensional Systems

Interplay between localization and the Kondo effect has been examined for a model two-dimensional system. Various physical quantities associated with localized spins are calculated perturbatively in terms of exchange coupling constant J and \(λ{=}/2πεFτ₀\) where ε F is the Fermi energy and τ 0 is the relaxation time of plane wave states; the susceptibility and the conductivity are shown to have quantum corrections proportional to λ J 2 ln 2 ( t ) and λ J 3 / t , respectively, where \(t{=}/2πτ₀kT\). It is discussed that the ground states of localized spins are qualitatively the same as in pure systems because the ensemble average of local densities of states defined by ≪ρ( ε 1 , r )ρ( ε 2 , r )…ρ( ε n , r )≫ appears to be non zero for any n in the limit of equal energies, ε i → ε F .