Significant reduction of electronic correlations upon isovalent Ru substitution of BaFe2As2

TL;DR

This study shows that substituting Ru for Fe in BaFe2As2 significantly reduces electronic correlations, alters carrier dynamics, and may facilitate superconductivity by weakening magnetism.

Contribution

It provides detailed experimental evidence that Ru substitution decreases correlation effects and modifies electronic structure without doping, advancing understanding of superconductivity emergence.

Findings

Fermi velocities increase with Ru substitution.

Electronic correlations are significantly reduced.

Carrier contributions to transport change with temperature.

Abstract

We present a detailed investigation of Ba(Fe0.65Ru0.35)2As2 by transport measurements and Angle Resolved photoemission spectroscopy. We observe that Fe and Ru orbitals hybridize to form a coherent electronic structure and that Ru does not induce doping. The number of holes and electrons, deduced from the area of the Fermi Surface pockets, are both about twice larger than in BaFe2As2. The contribution of both carriers to the transport is evidenced by a change of sign of the Hall coefficient with decreasing temperature. Fermi velocities increase significantly with respect to BaFe2As2, suggesting a significant reduction of correlation effects. This may be a key to understand the appearance of superconductivity at the expense of magnetism in undoped iron pnictides.