A close look at antiferromagnetism in multidimensional phase diagram of electron-doped copper oxide

TL;DR

This study investigates the complex interplay between antiferromagnetism and superconductivity in electron-doped copper oxides, revealing an extended AFM phase and multidimensional phase diagram through high-field measurements and oxygen tuning.

Contribution

It provides a systematic analysis of AFM behavior in electron-doped cuprates, highlighting the robustness of AFM phases and their relation to oxygen content and magnetic field.

Findings

Identification of two characteristic temperatures linked to AFM phases.

Observation of an extended AFM phase beyond previous limits.

Correlation between AFM and superconductivity interactions.

Abstract

Emergency of superconductivity at the instabilities of antiferromagnetism (AFM), spin/charge density waves has been widely recognized in unconventional superconductors. In copper-oxide superconductors, spin fluctuations play a predominant role in electron pairing with electron dopants yet composite orders veil the nature of superconductivity for hole-doped family. However, in electron-doped ones the ending point of AFM is still in controversy for different probes or its sensitivity to oxygen content. Here, by carefully tuning the oxygen content, a systematic study of Hall signal and magnetoresistivity up to 58 Tesla on optimally doped La2-xCexCuO4+-{\delta} (x = 0.10) thin films identifies two characteristic temperatures at 62.5+-7.5 K and 25+-5 K. The former is quite robust whereas the latter becomes flexible with increasing magnetic field, thereby linked to two- and three-dimensional AFM, evident from the multidimensional phase diagram as a function of oxygen as well as Ce dopants. Consequently, the observation of extended AFM phase in contrast to {\mu}SR probe corroborates an elevated critical doping in field, providing an unambiguous picture to understand the interactions between AFM and superconductivity.