Dissimilarities between the electronic structure of chemically doped and chemically pressurized iron pnictides from an angle-resolved photoemission spectroscopy study

TL;DR

This study uses angle-resolved photoemission spectroscopy to compare the electronic structure changes in EuFe2As2-xPx caused by chemical pressure versus doping, revealing non-rigid-band behavior linked to superconductivity.

Contribution

It provides new insights into how chemical pressure alters electronic structures differently from doping in iron pnictides, affecting superconductivity.

Findings

Electronic structure changes are orbital and kz dependent.

Fermi surface at the Brillouin zone corner remains largely unchanged.

Contrasts with rigid-band behavior observed in doped iron pnictides.

Abstract

We have studied the electronic structure of EuFe2As2-xPx using high resolution angle-resolved photoemission spectroscopy. Upon substituting As with the isovalent P, which leads to a chemical pressure and to superconductivity, we observe a non-rigid-band like change of the electronic structure along the center of the Brillouin zone (BZ): an orbital and kz dependent increase or decrease in the size of the hole pockets near the Gamma - Z line. On the other hand, the diameter of the Fermi surface cylinders at the BZ corner forming electron pockets, hardly changes. This is in stark contrast to p and n-type doped iron pnictides where, on the basis of ARPES experiments, a more rigid-band like behavior has been proposed. These findings indicate that there are different ways in which the nesting conditions can be reduced causing the destabilization of the antiferromagnetic order and the appearance of the superconducting dome.