First-principles study of the electronic structure of CaKRu4P4

The recent discovery and studies of 1144-phase compounds, e.g., CaKFe$_4$As$_4$, have attracted significant research interest. In this paper, based on the first-principles density functional calculations, we present a systematic study electronic structure recently synthetized 1144-type quaternary compound CaKRu$_4$P$_4$. We find that Ru-based possesses different from iron-based superconductors, even though they share very similar crystallographic structures. CaKRu$_4$P$_4$, there is no hole-type carrier if spin-orbit interaction not considered. And long-range magnetic order absent in its ground state. With application pressure, CaKRu$_4$P$_4$ becomes to those ternary 122-type compounds LaRu$_2$P$_2$ LaRu$_2$As$_2$. likely be phonon-mediated medium coupled BCS superconductor. Furthermore, type-I type-II Dirac fermions can created regulated system with pressure. therefore has potential an attractive platform for topological physics superconductivity.