Magnetic effect from non-magnetic impurity in superconducting CuO_{2} plane

TL;DR

This paper introduces a new model explaining how non-magnetic impurities like Zn in CuO₂ planes induce magnetic effects, leading to suppression of superconductivity and observable local density of states features.

Contribution

The paper presents a novel impurity model accounting for magnetic effects in non-magnetic impurity-doped cuprates, without relying on the unitary scattering limit.

Findings

Strong suppression of d-wave order parameter

Zero-energy resonance in local density of states

Spin polarization of charge carriers

Abstract

We propose a new model for impurity center formed by a cathion substitute for Cu, like Zn, in CuO_{2} planes. Its main effect on superconducting electrons is due to the non-zero exchange field on O sites, neighbors to the (non-magnetic) impurity. We discuss a strong suppression of d-wave order parameter, a zero- energy resonance in local density of states, and spin polarization of charge carriers, which can be related to the experimentally observed effects in Zn-doped copper oxides. These results are obtained \emph{without} using the unitary scattering limit.