Effect of Zn substitution for Cu on Ca$_{2-x}$Na$_{x}$CuO$_{2}$Cl$_{2}$ near the hole concentration of 1/8 per Cu

TL;DR

This study investigates how substituting Zn for Cu affects superconductivity in Ca_{2-x}Na_xCuO2Cl2 near the 1/8 hole concentration, revealing universal stripe correlations in high-T_c cuprates.

Contribution

It demonstrates that Zn substitution weakens superconductivity and induces stripe correlations, showing these effects are universal across different high-T_c cuprates.

Findings

Superconductivity is suppressed by Zn substitution near 1/8 hole doping.

Muon spin relaxation shows Cu spin fluctuations slow down below 5 K.

Zn induces stripe correlations similar to other cuprates.

Abstract

A weakening of superconductivity upon substitution of Cu by Zn (0.5~1 %) is observed in a high-T_c cuprate, Ca_{2-x}Na_xCuO2Cl2, near the hole concentration of 1/8 per Cu. The superconducting transition temperature and its volume fraction, estimated by magnetic susceptibility, exhibit a sizable anomaly for x=0.12~0.14, where the slowing down of Cu spin fluctuations below 5 K is demonstrated by muon spin relaxation experiments. These observations are in close resemblance to other typical cuprates including YBa2Cu3O_{7-d}, and Bi2Sr2Ca_{1-x}Y_xCu2O_{8+d}, providing further evidence that Zn-induced "stripe" correlation is a universal feature of high-T_c cuprate superconductors common to that of La_{2-x}A_{x}CuO4 (A=Ba, Sr).