A conducting nano-filament (CNF) network as a precursor to the origin of superconductivity in electron-doped copper oxides

TL;DR

This study reveals how conductive nano-filaments influence the emergence of superconductivity in electron-doped copper oxides, linking magnetic phase transitions with superconducting properties through detailed high-field measurements.

Contribution

It introduces the concept of conducting nano-filament networks as a precursor to superconductivity, supported by experimental data and theoretical analysis in electron-doped cuprates.

Findings

Identification of two characteristic temperatures linked to AFM states.

Evidence of nano-filamentary structures affecting superconductivity.

A new phase diagram connecting oxygen content, doping, and magnetic states.

Abstract

Emergency of superconductivity at the instabilities of antiferromagnetism 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 copper oxide superconductors (cuprates) the AFM critical end point is still in controversy for different probes, demonstrating high sensitivity to oxygen content. Here, by carefully tuning the oxygen content, a systematic study of the Hall signal and magnetoresistivity up to 58 Tesla on LCCO thin films identifies two characteristic temperatures. The former is quite robust, whereas the latter becomes flexible with increasing magnetic field, thereby linking respectively to two- and three-dimensional AFM, evident from the multidimensional phase diagram as a function of oxygen and Ce dopants. A rigorous theoretical analysis of the presented data suggest the existence of conductive nano-filamentary structures that effectively corroborate all previously reported field studies. The new findings provide a uniquely consistent alternative picture in understanding the interactions between AFM and superconductivity in electron-doped cuprates and offer a consolidating interpretation to the pioneering scaling law in cuprates recently established by Bozovic et al. (Nature, 2016)