Cu NQR Wipeout Effect versus Charge Pseudogap in Zn/Ni Doped NdBa$_{2}$Cu$_{3}$O$_{6+y}$

TL;DR

This study investigates how Ni and Zn impurities affect magnetic correlations and the charge pseudogap in underdoped NdBa2Cu3O6+y, revealing a link between impurity-induced magnetism and pseudogap behavior.

Contribution

It provides new insights into how Ni and Zn impurities differently influence magnetic correlations and the pseudogap in cuprate superconductors.

Findings

Ni enhances magnetic correlations and causes NQR wipeout.

Zn suppresses magnetism and shows no wipeout effect.

Impurity effects correlate with pseudogap behavior.

Abstract

We report $^{63,65}$Cu NQR measurements on slightly underdoped NdBa$_{2}$Cu$_{3}$O$_{6+y}$ single crystals heavily doped by Ni and Zn impurities. Owing to the impurity doping superconductivity is fully suppressed in both cases. The Ni strongly enhances magnetic correlations and induces a wipeout of the NQR signal comparable to that found in stripe ordered lanthanum cuprates. In contrast, the magnetism is suppressed in the Zn doped sample where no wipeout effect is observed and the nuclear spin relaxation rate is reduced. Our findings are in a striking correspondence with the different impact of Ni and Zn impurities on the charge pseudogap evidenced by recent optical data, uncovering thereby a close relationship between the magnetic correlations and pseudogap phenomena.