Dopant-modulated pair interaction in cuprate superconductors

TL;DR

This paper demonstrates that out-of-plane dopant atoms in cuprate superconductors locally modulate the pairing interaction, explaining nanoscale electronic inhomogeneity observed in STM experiments.

Contribution

It introduces a model where dopant atoms influence pair interactions on a lattice scale, aligning with experimental STM data and revealing the importance of dopant-induced disorder.

Findings

Dopant atoms modulate pair interaction locally.

The model reproduces STM-observed correlations.

Dopant effects occur on a length scale of about one lattice constant.

Abstract

Comparison of recent experimental STM data with single-impurity and many-impurity Bogoliubov-de Gennes calculations strongly suggests that random out-of-plane dopant atoms in cuprates modulate the pair interaction locally. This type of disorder is crucial to understanding the nanoscale electronic structure inhomogeneity observed in BSCCO-2212, and can reproduce observed correlations between the positions of impurity atoms and various aspects of the local density of states such as the gap magnitude and the height of the coherence peaks. Our results imply that each dopant atom modulates the pair interaction on a length scale of order one lattice constant.