Electronic Structure of InCo2As2 and KInCo4As4: LDA + DMFT.

A comparative analysis of the electronic structure obtained in the DFT/LDA and LDA + DMFT approaches of the possible isostructural analogues of iron superconductors InCo₂As₂ and KInCo₄As₄ with the electronic structure of the parent high-temperature superconductor system BaFe₂As₂ is carried out. It is established that in spite of the rather large value of the electron-electron correlations (local Coulomb interaction on the Co- shell eV, the Hund exchange interaction eV), in the considered systems a relatively small quasiparticle mass renormalization 1.2–1.35 at the Fermi level is observed. The correlation effects lead to the remarkable shift and compression of the spectrum below –0.8 eV. The band structure of InCo₂As₂ near the Fermi level is qualitatively similar to the previously studied BaCo₂As₂, and differs significantly from the band structure of BaFe₂As₂. In the KInCo₄As₄ system, the bands near the Fermi level resemble the band structure of BaFe₂As₂, and the Fermi surfaces have a similar topology. This indirectly points to the possibility of superconductivity in KInCo₄As₄. Also according to the results of LDA + DMFT calculations it is seen that with a rather small hole or electron doping in the KInCo₄As₄ system will experience topological Lifshitz transitions. We believe that the synthesis of the InCo₂As₂ and KInCo₄As₄ compounds considered in this paper is important for the study of superconductivity in this class of materials. [ABSTRACT FROM AUTHOR]