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

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.

Figures (3)

• Figure 1: Crystal structure of (a) LNO-4310, (b) LCO-4310 and (c) LCO-NiCl.
• Figure 2: Imaginary parts of the self-energy at 290 K for LCO-NiCl. (a) Matsubara-frequency self-energy $\mathrm{Im\Sigma(i\omega_n)}$. (b) Real-frequency self-energy $\mathrm{Im\Sigma(\omega)}$.
• Figure 3: DFT band structures are shown in the upper panels, where the orbital weights are represented by the size of the colored circles. The momentum-resolved spectral functions $\mathrm{A(\mathbf{k},\omega)}$ and density of states obtained by DFT+DMFT at 290 K are displayed in the lower panels. The white and black dashed lines at 0 eV denote the Fermi level.