Comment on "Localized behavior near the Zn impurity in YBa2Cu4O8 as measured by nuclear quadrupole resonance"

TL;DR

This paper critiques recent claims denying staggered magnetic moments near Zn impurities in YBCO superconductors, arguing that previous interpretations of NMR and NQR data are flawed and supporting the existence of localized magnetic moments.

Contribution

The authors demonstrate that the conclusions dismissing magnetic moments near Zn impurities are based on misinterpretations of experimental NMR and NQR data.

Findings

Previous claims are based on erroneous data interpretation.

Evidence supports localized magnetic moments near Zn impurities.

Contradicts recent claims denying magnetic moments in YBCO.

Abstract

Williams and Kramer [Phys. Rev. B {\bf 64}, 104506 (2001)] have recently argued against the existence of staggered magnetic moments residing on several lattice sites around Zn impurities in YBCO superconductors. This claim, which is in line with an earlier publication by Williams, Tallon and Dupree [Phys. Rev. B {\bf 61}, 4319 (2000)], is however in contradiction with a large body of experimental data from different NMR groups. On the contrary, the authors argue in favor of a very localized spin and charge density on Cu sites first neighbors to Zn. We show that the conclusions of Williams and Kramer arise from erroneous interpretations of NMR and NQR data.