Electronic structure and correlation of La$_4$Co$_2$NiO$_8$Cl$_2$: a theoretical proposal for a La$_4$Ni$_3$O$_{10}$-like high-temperature superconductor

TL;DR

This paper proposes a new Co-based compound, La$_4$Co$_2$NiO$_8$Cl$_2$, with electronic properties similar to high-pressure La$_4$Ni$_3$O$_{10}$, potentially hosting high-temperature superconductivity, based on DFT+DMFT calculations.

Contribution

The study introduces a theoretically predicted La$_4$Co$_2$NiO$_8$Cl$_2$ compound with similar structure and electronic correlations to high-pressure La$_4$Ni$_3$O$_{10}$, suggesting it could be a high-temperature superconductor.

Findings

La$_4$Co$_2$NiO$_8$Cl$_2$ has a structure similar to La$_4$Ni$_3$O$_{10}$ under high pressure.

The electronic structure of La$_4$Co$_2$NiO$_8$Cl$_2$ is strongly correlated, akin to the high-pressure nickelate.

The compound may host high-temperature superconductivity based on its electronic properties.

Abstract

Based on the discovery of high-temperature superconductivity in the bilayer nickelate La$_3$Ni$_2$O$_7$, several Co-based La$_3$Ni$_2$O$_7$-like materials were theoretically predicted as possible high-temperature superconductors by electron doping. Motivated by these findings and the subsequent discovery of superconductivity in the trilayer nickelate La$_4$Ni$_3$O$_{10}$ under high pressure, we propose and investigate a Co-based La$_4$Ni$_3$O$_{10}$-like material. With electron doping to the high-pressure trilayer cobaltate La$_4$Co$_3$O$_{10}$, using density functional theory combined with dynamical mean-field theory (DFT+DMFT), we find that the resulting compound La$_4$Co$_2$NiO$_8$Cl$_2$ exhibits a crystal structure and a strongly correlated electronic structure similar to those of La$_4$Ni$_3$O$_{10}$ under high pressure. This suggests that this new compound may host high-temperature superconductivity.