Experimental and theoretical electronic structure of EuRh 2 As 2

Abstract

The Fermi surfaces (FS's) and band dispersions of EuRh 2As 2 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 Γ (0,0) and X (π,π) points. Interesting changes in band folding are predicted by the theoretical calculations below the magnetic transition temperature T N≈47 K. However, by comparing the FS's measured at 60 and 40 K, 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 (≈25 K) where changes are observed in the Hall coefficient. Notably, the Fermi surface deviates drastically from the usual FS of the superconducting iron-based AFe 2As 2 parent compounds, including the absence of nesting between the Γ and X FS pockets.