Local Magnetic Moments in Nanoscale Systems

The formation of local magnetic moments and its size effect in one- and three-dimension finite systems with magnetic impurity are investigated based on the Anderson hybridizing model in real space. By the exact diagonalization within the self-consistent mean field approximation, it is found that as contrast to that in infinite system, the formation of the local magnetic moment in finite system may strongly depend on the size of system up to a few nanometers. The spectral densities of the local electronic states and the spatial distribution of the magnetic moments for the conduction electrons polarized by the local moment are also obtained. The condition for the occurrence of local magnetic moments in such small systems is discussed. The strong size-dependence of the local magnetic moments in finite system is attributed to the quantum size effect.