Local electronic structure near oxygen dopants in BSCCO-2212: a window on the high-Tc pair mechanism?

TL;DR

This study uses density functional theory to identify favorable oxygen dopant locations in BSCCO-2212 and examines how these dopants influence local electronic structure, shedding light on the high-temperature superconductivity mechanism.

Contribution

It provides a detailed theoretical analysis of oxygen dopant positions and their effects on local electronic properties in BSCCO-2212, supporting experimental STM findings.

Findings

Support for STM resonance identification with interstitial oxygen

Localization of electronic structure modifications near dopants

Insights into dopant-induced variations in superconducting gap

Abstract

The cuprate material BSCCO-2212 is believed to be doped by a combination of cation switching and excess oxygen. The interstitial oxygen dopants are of particular interest because scanning tunnelling microscopy (STM) experiments have shown that they are positively correlated with the local value of the superconducting gap, and calculations suggest that the fundamental attraction between electrons is modulated locally. In this work, we use density functional theory to try to ascertain which locations in the crystal are energetically most favorable for the O dopant atoms, and how the surrounding cage of atoms deforms. Our results provide support for the identification of STM resonances at -1eV with dopant interstitial O atoms, and show how the local electronic structure is modified nearby.