Non-Fermi-liquid properties in disordered Kondo systems

We investigate the Kondo effect in disordered electron systems using a finite temperature quantum Monte Carlo method. Depending on the position of a magnetic impurity, the local moment is screened or unscreened by the spin of the conduction electron. The results indicate that the Kondo temperature has a spatial distribution. We show that the distribution of the Kondo temperature becomes wide and the weight at T-K = 0 becomes large as randomness increases. When randomness increases, the average susceptibility exhibits a logarithmic divergence, indicating that the observable susceptibility shows a non-Fermi-liquid behaviour at low temperatures.