RKKY interaction in metals with impurities

(Submitted 27 December 1985) Pis'ma Zh. Eksp. Teor. Fiz. 43, No. 4, 190-192 (25 February 1986) The magnitude of the R K K Y interaction in a metal with impurities is derived. The impurities are shown to cause a random phase shift of the R K K Y interaction, but they do not cause an exponential decay of this interaction over distances on the order of the electron mean free path. This decay is found only for the interaction averaged over impurity configurations. However, it is meaningless to use such an average because of the pronounced dispersion of the interaction in the region in which the exponential factor is small.