Superconductivity and Field-Induced Magnetism in Pr$_{2-x}$Ce$_x$CuO$_4$ Single Crystals

TL;DR

This study uses muon-spin rotation to reveal coexistence of superconductivity and static magnetism in Pr$_{2-x}$Ce$_x$CuO$_4$, showing magnetic order emergence below T_c and similarities with hole-doped cuprates.

Contribution

It provides new insights into the coexistence of superconductivity and magnetism in electron-doped cuprates through muSR measurements.

Findings

Superconductivity coexists with static Cu spin magnetism.

Magnetic order appears below T_c in the vortex state.

In-plane magnetic penetration depth resembles hole-doped cuprates at high temperatures.

Abstract

We report muon-spin rotation/relaxation (muSR) measurements on single crystals of the electron-doped high-T_c superconductor Pr$_{2-x}$Ce$_x$CuO$_4$. In zero external magnetic field, superconductivity is found to coexist with Cu spins that are static on the muSR time scale. In an applied field, we observe a Knight shift that is primarily due to the magnetic moment induced on the Pr ions. Below the superconducting transition temperature T_c, an additional source of static magnetic order appears throughout the sample. This finding is consistent with antiferromagnetic ordering of the Cu spins in the presence of vortices. We also find that the temperature dependence of the in-plane magnetic penetration depth in the vortex state resembles that of the hole-doped cuprates at temperatures above ~ 0.2 T_c.