Electronic structure and superconducting properties of LaNiO${}_2$

Abstract

Motivated by recent photoemission measurements on the La${}_{0.8}$Sr${}_{0.2}$NiO${}_2$, we carry out a systematic study of the infinite-layer nickelate using both dynamical mean-field theory and density matrix embedding theory. The renormalized electronic structure and Fermi surface of correlated La${}_{0.8}$Sr${}_{0.2}$NiO${}_2$ are studied in an effective two-band model through the dynamical mean-field calculation. We find the correlation effects reflect mainly on the Ni $d$ band, which is consistent with the experimental findings. We further study the ground state including magnetism and superconductivity through the density matrix embedding theory. Within the experimental doping range and rigid-band approximation, we show that the $d$-wave superconductivity is the lowest energy state, while the static magnetism is absent except very close to zero doping. These findings provide a new understanding of infinite-layer nickelate superconductivity.

6 pages, 3 figures and Supplemental Material