ARPES studies of the electronic structure of LaOFe(P,As)

TL;DR

This study compares the electronic structures of LaOFeP and LaOFeAs using ARPES, revealing both common features and key differences, and discusses implications for understanding their superconductivity mechanisms.

Contribution

It provides the first detailed ARPES comparison of LaOFeP and LaOFeAs, highlighting the differing agreement with band structure calculations and suggesting different theoretical approaches.

Findings

LaOFeP data agrees with LDA calculations, indicating itinerant electrons.

LaOFeAs shows poor agreement with LDA, especially around (pi,pi).

Differences suggest varied electronic behaviors in these compounds.

Abstract

We report a comparison study of LaOFeP and LaOFeAs, two parent compounds of recently discovered iron-pnictide superconductors, using angle-resolved photoemission spectroscopy. Both systems exhibit some common features that are very different from well-studied cuprates. In addition, important differences have also been observed between these two ferrooxypnictides. For LaOFeP, quantitative agreement can be found between our photoemission data and the LDA band structure calculations, suggesting that a weak coupling approach based on an itinerant ground state may be more appropriate for understanding this new superconducting compound. In contrast, the agreement between LDA calculations and experiments in LaOFeAs is relatively poor, as highlighted by the unexpected Fermi surface topology around (pi,pi). Further investigations are required for a comprehensive understanding of the electronic structure of LaOFeAs and related compounds.