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

摘要

We have studied the electronic structure of EuFe2As2-xPx using highresolution angle-resolved photoemission spectroscopy. Upon substituting As withthe isovalent P, which leads to a chemical pressure and to superconductivity,we observe a non-rigid-band like change of the electronic structure along thecenter of the Brillouin zone (BZ): an orbital and kz dependent increase ordecrease in the size of the hole pockets near the Gamma - Z line. On the otherhand, the diameter of the Fermi surface cylinders at the BZ corner formingelectron pockets, hardly changes. This is in stark contrast to p and n-typedoped iron pnictides where, on the basis of ARPES experiments, a morerigid-band like behavior has been proposed. These findings indicate that thereare different ways in which the nesting conditions can be reduced causing thedestabilization of the antiferromagnetic order and the appearance of thesuperconducting dome.