Kondo anomaly of impurity spin resonance linewidth

Abstract

Using the method of Baym and Kadanoff a kinetic equation is derived for the impurity susceptibility in thes-d model. Summing up the most important diagrams the impurity self-energy can be expressed in terms of Suhl'sT-matricest andτ. The contribution of the spin non flip amplitudet to the spin relaxation time is cancelled by a corresponding vertex correction. Thus the final result can be expressed in terms of the spin flip amplitudeτ alone which causes an anomalous temperature dependence of the relaxation time.