Spin-lattice relaxation rate of a magnetic impuritiy in the spin degenerate Anderson model

The renormalization group formalism was applied to calculate the spinlattice relaxation rate T 1 of a well-defined magnetic moment in the neighborhood of a spin degenerate Anderson impurity. In the Kondo regime, T 1 in function of the temperature T presents a peak at the Kondo temperature Tk; for T ≪ Tk, the system behaves as a heavy Fermy liquid, with an enhanced density of states, which increases with the decreasing of the Kondo temperature; T 1 T remains an universal function of T/Γk up to temperatures the order of 100Γk , where Γk is the Kondo width; for temperatures lower then Tk, the spin relaxation rate, T −1 1 , is proportional to the magnetic susceptibility multiplied by the temperature, χT ; the peak of T 1 at the Kondo temperature decreases with the increasing of the distance between the Anderson impurity and the magnetic probe. The authors would like to thank Ufam (the Amazonas Federal University) and CNPq/Brazil for the financial support.