Lanthanide substitution effects in electron-doped high-Tc superconductors studied by angle-resolved photoemission spectroscopy

TL;DR

This study uses angle-resolved photoemission spectroscopy to compare the effects of antiferromagnetism in two electron-doped high-Tc superconductors, revealing differences in energy gaps and magnetic interactions.

Contribution

It provides a direct comparison of antiferromagnetic effects in Sm- and Eu-based electron-doped superconductors using ARPES data.

Findings

Larger energy gap in ECCO indicates stronger antiferromagnetic effects.

Band dispersions align with tight-binding calculations, confirming magnetic influences.

Antiferromagnetism impacts the electronic structure near the Fermi level.

Abstract

We have performed an angle-resolved photoemission study of the electron-doped high-Tc superconductors (HTSCs) Sm_{1.85}Ce_{0.15}CuO_{4} (SCCO) and Eu_{1.85}Ce_{0.15}CuO_{4} (ECCO). Around the nodal point (pi/2, pi/2), we observed an energy gap at the Fermi level (EF) for both samples, resulting from the strong effects of antiferromagnetism. The magnitude of this gap in ECCO is larger than that in SCCO, implying that the effects of antiferromagnetism in ECCO are stronger than that in SCCO. Also, we quantitatively confirmed the effects of antiferromagnetism by the band dispersions to tight-binding calculation.