Field-induced local moments around nonmagnetic impurities in metallic cuprates

We consider a defect in a strongly correlated host metal and discuss, within a slave-boson mean field formalism for the t-t(')-J model, the formation of an induced paramagnetic moment which is extended over nearby sites. We study in particular an impurity in a metallic band, suitable for modeling the optimally doped cuprates, in a regime where the impurity moment is paramagnetic. The form of the local susceptibility as a function of temperature and doping is found to agree well with recent NMR experiments, without including screening processes leading to the Kondo effect.