Kondo effect in systems with spin disorder

We consider the role of static disorder in the spin sector of the one- and two-channel Kondo models. The distribution functions of the disorder-induce d effective energy splitting between the two levels of the Kondo impurity a re derived to the lowest order in the concentration of static scatterers. I t is demonstrated that the distribution functions are strongly asymmetric, with the typical splitting being parametrically smaller than the average rm s value. We employ the derived distribution function of splittings to analy ze the temperature dependence of the low-temperature conductance of a sampl e containing an ensemble of two-channel Kondo impurities. The results are u sed to analyze the consistency of the two-channel Kondo interpretation of t he zero-bias anomalies observed in Cu/(Si:N)/Cu nanoconstrictions. [S0163-1 829(99)06737-5].