Dynamical Susceptibility of a Dilute Magnetic Alloy in the Anderson Model

The random-phase-approximation derivation of the dynamical susceptibility in the magnetic limit of the Anderson model is presented. The corresponding Bloch equations are found to differ in several ways from those obtained in the exchange model. For $g_e\ne g_d$, the magnetizations transferred between the localized and conduction electrons by the admixture are not equal. Their difference is experienced by the impurity as a local "field" and alters the resonance condition. The internal field experienced by the conduction electrons is proportional to the difference between the redistribution and admixture polarizations. In contrast to results derived by Sasada and Hasegawa, the spins relax towards the local instantaneous field.