# Muon spin relaxation study of the spin correlation in the overdoped regime of electron-doped high-Tc cuprate superconductors

## TL;DR

This study uses muon spin relaxation to explore how Cu-spin correlations evolve in electron-doped cuprates and their potential link to superconductivity across different doping levels.

## Contribution

It provides new evidence that Cu-spin correlations are present in the overdoped regime and may be integral to the superconducting mechanism in electron-doped cuprates.

## Key findings

- Cu-spin correlation develops in overdoped samples with superconductivity
- The correlation weakens as doping increases and is negligible in heavily overdoped samples
- Cu-spin correlation exists across doping regimes, suggesting a role in superconductivity

## Abstract

In order to investigate the low-energy antiferromagnetic Cu-spin correlation and its relation to the superconductivity, we have performed muon spin relaxation (muSR) measurements using single crystals of the electron-doped high-Tc cuprate Pr_1-x_LaCe_x_CuO_4_ in the overdoped regime. The muSR spectra have revealed that the Cu-spin correlation is developed in the overdoped samples where the superconductivity appears. The development of the Cu-spin correlation weakens with increasing x and is negligibly small in the heavily overdoped sample where the superconductivity almost disappears. Considering that the Cu-spin correlation also exist in the superconducting electron-doped cuprates in the undoped and underdoped regimes [T. Adachi et al., J. Phys. Soc. Jpn. 85, 114716 (2016)], our findings suggest that the mechanism of the superconductivity is related to the low-energy Cu-spin correlation in the entire doping regime of the electron-doped cuprates.