Orbital Symmetry of Ba(Fe1-xCox)2As2 Superconductors Probed with X-ray Absorption Spectroscopy

TL;DR

This study uses X-ray absorption spectroscopy to investigate the orbital symmetries and electronic structure of electron-doped Ba(Fe1-xCox)2As2 superconductors, revealing hybridization and itinerancy consistent with theoretical predictions.

Contribution

It provides detailed experimental insights into the orbital symmetries and electronic structure of Ba(Fe1-xCox)2As2 superconductors, confirming theoretical models.

Findings

Fe d electron itinerancy observed

Weak electronic correlations detected

Strong Fe-As hybridization at the Fermi level

Abstract

The orbital symmetries of electron doped iron-arsenide superconductors Ba(Fe1-xCox)2As2 have been measured with x-ray absorption spectroscopy. The data reveal signatures of Fe d electron itinerancy, weak electronic correlations, and a high degree of Fe-As hybridization related to the bonding topology of the Fe dxz+yz states, which are found to contribute substantially at the Fermi level. The energies and detailed orbital character of Fe and As derived unoccupied s and d states are found to be in remarkably good agreement with the predictions of standard density functional theory.