Out-of-plane impurities induced the deviation from the monotonic d-wave superconducting gap in cuprate superconductors

TL;DR

This paper investigates how out-of-plane impurities affect the electronic structure and superconducting gap in cuprate superconductors, revealing deviations from the expected monotonic d-wave gap with increasing impurity concentration.

Contribution

It introduces a kinetic energy driven mechanism analysis showing how out-of-plane impurities cause non-monotonic deviations in the superconducting gap of cuprates.

Findings

Superconducting coherence peaks are suppressed with more impurities.

The nodal gap position remains unchanged despite impurities.

The antinodal gap shifts to higher binding energies with impurities.

Abstract

The electronic structure of cuprate superconductors is studied within the kinetic energy driven superconducting mechanism in the presence of the out-of-plane impurities. With increasing the impurity concentration, although both superconducting coherence peaks around nodal and antinodal regions are suppressed, the position of the leading-edge mid-point of the electron spectrum around the nodal region remains at the same position, while it is shifted towards higher binding energies around the antinodal region, this leads to a strong deviation from the monotonic d-wave superconducting gap in the out-of-plane impurity-controlled cuprate superconductors.