Experimental and theoretical electronic structure of EuRh2As2

TL;DR

This study investigates the electronic structure of EuRh2As2 using ARPES and theoretical calculations, revealing temperature-independent Fermi surfaces and significant deviations from typical iron-based superconductors.

Contribution

It provides detailed experimental and theoretical analysis of EuRh2As2's electronic structure, highlighting weak magnetic coupling and unique Fermi surface features.

Findings

Fermi surfaces match calculations at high temperature

No observable Fermi surface change across magnetic transition

Distinct Fermi surface from typical iron-based superconductors

Abstract

The Fermi surfaces (FS's) and band dispersions of EuRh2As2 have been investigated using angle-resolved photoemission spectroscopy. The results in the high-temperature paramagnetic state are in good agreement with the full potential linearized augmented plane wave calculations, especially in the context of the shape of the two-dimensional FS's and band dispersion around the Gamma (0,0) and X (pi,pi) points. Interesting changes in band folding are predicted by the theoretical calculations below the magnetic transition temperature Tn=47K. However, by comparing the FS's measured at 60K and 40K, we did not observe any signature of this transition at the Fermi energy indicating a very weak coupling of the electrons to the ordered magnetic moments or strong fluctuations. Furthermore, the FS does not change across the temperature (~ 25K) where changes are observed in the Hall coefficient. Notably, the Fermi surface deviates drastically from the usual FS of the superconducting iron-based AFe2As2 parent compounds, including the absence of nesting between the Gamma and X FS pockets.