Kondo effect of non-magnetic impurities and the co-existing charge order in the cuprate superconductors

TL;DR

This paper develops a theoretical framework to understand the Kondo effect caused by induced magnetic moments near non-magnetic impurities in cuprate superconductors, considering the coexistence of charge order and superconductivity.

Contribution

It introduces a novel bond-operator theory approach to describe the induced moments and Kondo effect in the presence of charge order and superconductivity in cuprates.

Findings

Local density of states shows a low-energy peak within the superconducting gap.

Charge order can be enhanced near impurities.

The theory explains experimental observations of impurity-induced magnetic effects.

Abstract

We present a theory of Kondo effect caused by an induced magnetic moment near non-magnetic impurities such as Zn and Li in the cuprate superconductors. Based on the co-existence of charge order and superconductivity, a natural description of the induced moment and the resulting Kondo effect is obtained in the framework of bond-operator theory of microscopic t-J-V Hamiltonian. The local density of state near impurities is computed in a self-consistent Bogoliubov-de Gennes theory which shows a low-energy peak in the middle of superconducting gap. Our theory also suggests that the charge order can be enhanced near impuries.