ABSTRACT
This chapter presents a brief overview of the physical problem, including behavior at not very low temperatures. It briefly discusses Kondo's approach and Nozieres' analysis. In 1976, Nozieres assumed that P. W. Anderson's conjecture was correct and presented a phenomenological "Fermi liquid" model that enabled a theoretical derivation of the numerical results obtained by Wilson. Somehow the impurity affects the susceptibility twice as much as it affects the specific heat when compared with the corresponding result for a Fermi gas. Effects of magnetic impurities on the properties of metals have been known since the 1930s. The impurity spin induces an effective repulsive interaction of the electrons. This system of interacting electrons can be described using Fermi liquid theory. The impurity resistivity and susceptibility resemble the corresponding behaviors found in the resistivity and Pauli spin susceptibility of a Fermi liquid.
