Finite-size study of a magnetic impurity in a strongly correlated electronic system

Abstract

Using numerical exact diagonalization techniques we study the zero-temperature properties of a substitutional magnetic impurity in a one-dimensional correlated system described by the repulsive Hubbard model. We calculate the static spin and charge correlation functions and find that, while the spin correlation maintains a 2 k F periodicity when increasing the Hubbard U, the charge correlations show Friedel oscillations with a 4 k F periodicity for large values of U. We also present results for the static susceptibility at the impurity site. This susceptibility shows a non-monotonic behaviour as a function of U for the doped case. For small values of U the Kondo singlet seems to be more strongly bounded than in the non-interacting ( U = 0) case.