Spin Relaxation and Transport in Local-Moment Systems

Using a kinetic equation, the effect of Kondo-type anomalies on spin relaxation and transport in local-moment systems is studied. For zero wave number of the external magnetic field a modified Hasegawa equation can be derived. With increasing wave number a diffusion regime is reached. The diffusion constant can be related to the electrical resistivity. Further increase of the wave number yields a collisionless regime for the conduction electrons. In this regime, the spin relaxation becomes essentially unbottlenecked, and the local-moment relaxation proceeds with the full (anomalous) Korringa value.