Kondo screening cloud in a one-dimensional wire: Numerical renormalization group study

Abstract

We study the Kondo model---a magnetic impurity coupled to a one-dimensional wire via exchange coupling---by using Wilson's numerical renormalization group technique. By applying an approach similar to which was used to compute the two-impurity problem we managed to improve the poor spatial resolution of the numerical renormalization group method. In this way we have calculated the impurity-spin--conduction-electron-spin correlation function which is a measure of the Kondo compensation cloud whose existence has been a long-standing problem in solid-state physics. We also present results on the temperature dependence of the Kondo correlations.