Observation of the weak electronic correlations in KFeCoAs₂ (3d ⁶): an isoelectronic to the parent compounds of 122 series of iron pnictides BaFe₂As₂

Abstract

Using the angle-resolved photoemission spectroscopy and band structure calculations we study the electronic structure of KFeCoAs, which is isoelectronic to the parent material of 122 series of iron-based superconductors BaFeAs. Although band structure calculations predict nearly identical dispersions of the electronic states in both compounds, experiment reveals drastic differences in both the global renormalization and Fermi surfaces. On the basis of the comparison of electronic structures of these two isoelectronic compounds, we demonstrate local magnetic correlations as a vital role for the peculiar low-energy electron dynamics of iron-based superconductors.

Evidence of topological nodal lines and surface states in the centrosymmetric superconductor SnTaS2

“…We extract the Fermi surfaces from the experimental observation on the k z ∼ 0 plane, as shown in Fig. 3 [48,50]. This effect can be more clearly seen within a wide energy range in the whole BZ, as discussed in Fig.…”