The Figure below shows the Fermi surfaces for InCo2As2 (panel (a)) and KInCo4As4 (panel (b)) obtained in LDA. For InCo2As2, all large sheets of the Fermi surface are concentrated around the corners of the Brillouin zone. For InCo2As2, all Fermi surface sheets have a pronounced kz-dependence. In the KInCo4As4 system, where the K- and In- layers of the crystal structure are interchanged, the Fermi surface becomes practically quasi-two-dimensional (panel (b)). It can also be seen in the band structure in the G-M and M-A directions near the Fermi level are almost identical (Panel (b)) in contrast to InCo2As2 (panel (а)). The Fermi surface for KInCo4As4 is similar to that of iron-containing superconductors, but the shape of the Fermi surface sheets near the G-point is closer to a rectangular prism than to a cylinder. This shape of the Fermi surface sheets may facilitate nesting. Experimental synthesis and study of the KInCo4As4 samples is interesting for testing the occurence of superconductivity.

DFT/LDA calculated Fermi surfaces for InCo2As2 (panel (a)) and KInCo4As4 (panel (b)).

N.Pavlov, I.Shein, K.Pervakov, I.Nekrasov
JETP Letters 117, issue 1 (2023)