Field-induced local moments around nonmagnetic impurities in metallic cuprates

TL;DR

This paper models how nonmagnetic impurities induce extended local moments in metallic cuprates using a slave boson mean field approach, matching experimental NMR data without Kondo screening.

Contribution

It introduces a theoretical framework for impurity-induced local moments in cuprates that aligns with experimental observations, without relying on Kondo screening effects.

Findings

Local susceptibility matches NMR data

Impurity moments are extended over nearby sites

Model reproduces temperature and doping dependence

Abstract

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 modelling 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.