Hole Binding around Ni Impurity in Cuprates

TL;DR

This study investigates how Ni impurities affect hole distribution in cuprates, revealing hole binding around Ni that influences modeling and suggesting an experimental verification via resonant inelastic x-ray scattering.

Contribution

It provides the first detailed numerical analysis of hole binding around Ni impurities in cuprates, highlighting the importance of O2p orbitals and proposing an experimental approach.

Findings

Hole predominantly binds to O2p orbitals around Ni

Formation of Zhang-Rice doublet around Ni impurity

Implications for modeling Ni-substituted cuprates

Abstract

We examine the influence of Ni impurity in cuprates on the distribution of hole carriers by performing numerically exact diagonalization calculations for a model consisting of Cu3d, Ni3d, and O2p orbitals. Using realistic parameters for the system, we find that a hole is predominantly bound to O2p orbitals around the Ni impurity forming the Zhang-Rice doublet. This imposes strong restrictions on modeling Ni-substituted cuprates. We propose a resonant inelastic x-ray scattering experiment for Ni K-edge to confirm hole binding around the Ni impurity.