Extended superconducting dome of electron-doped cuprates after protect annealing revealed by ARPES

TL;DR

This study uses ARPES to show that protect annealing extends the superconducting dome in electron-doped cuprates, revealing higher electron concentrations and broader superconductivity than conventional methods.

Contribution

It demonstrates that protect annealing significantly alters the electronic structure and superconducting phase diagram of PLCCO, expanding the SC dome beyond previous limits.

Findings

Protect annealing increases the actual electron concentration (nFS) beyond Ce doping levels.

The SC dome in PLCCO is broader and extends further into the overdoped region.

ARPES reveals a larger Fermi surface area indicating higher electron doping.

Abstract

The electron-doped cuprates are usually characterized by a more robust antiferromagnetic phase and a much narrower superconducting (SC) dome than those of the hole-doped counterparts. Recently, bulk single crystals of Pr1.3-xLa0.7CexCuO4-{\delta} (PLCCO) prepared by the protect annealing method have been studied extensively and revealed many intriguing properties that were different from those obtained from samples annealed by the conventional methods. Here, we report on a systematic angle-resolved photoemission spectroscopy study of PLCCO single crystals after protect annealing. The results indicate that the actual electron concentration (nFS ) estimated from the Fermi-surface area is significantly larger than the Ce concentration x and the new nFS-based SC dome of PLCCO is more extended towards the overdoped side than the x-based SC dome derived for samples prepared using the conventional annealing method.