Field-Induced Uniform Antiferromagnetic Order Associated with Superconductivity in Pr$_{1-x}$LaCe$_{x}$CuO$_{4-\delta}$

TL;DR

This study reveals a strong correlation between field-induced antiferromagnetic order and superconductivity in electron-doped cuprate Pr$_{1-x}$LaCe$_{x}$CuO$_{4- abla}$, showing that AF order can be induced by magnetic fields even in superconducting states.

Contribution

The paper demonstrates the occurrence of uniform field-induced AF order in electron-doped cuprates and contrasts it with hole-doped cuprates, highlighting differences in flux line core behavior.

Findings

Field-induced AF order observed in multiple doping levels.

AF order is not confined to flux line cores, unlike hole-doped cuprates.

Anomalous hyperfine coupling between muons and Pr ions identified.

Abstract

Strong correlation between field-induced antiferromagnetic (AF) order and superconductivity is demonstrated for an electron-doped cuprate superconductor, Pr$_{1-x}$LaCe$_{x}$CuO$_{4-\delta}$ (PLCCO). In addition to the specimen with $x=0.11$ (which is close to the AF phase boundary, $x\simeq0.10$), we show that the one with $x=0.15$ ($T_c\simeq16$ K at zero field) also exhibits the field-induced AF order with a reduced magnitude of the induced moment. The uniform muon Knight shift at a low magnetic field ($\sim10^2$ Oe) indicates that the AF order is not localized within the cores of flux lines, which is in a marked contrast with theoretical prediction for hole-doped cuprates. The presence of anomalous non-diagonal hyperfine coupling between muons and Pr ions is also demonstrated in detail.