Electronic structure and superconducting properties of LaNiO$_2$

TL;DR

This paper investigates the electronic structure and potential superconductivity of LaNiO₂ using advanced theoretical methods, revealing dominant correlation effects on Ni d bands and suggesting d-wave superconductivity near optimal doping.

Contribution

It provides a systematic theoretical study combining dynamical mean-field theory and density matrix embedding theory to understand nickelate superconductivity, highlighting the role of correlations and magnetic states.

Findings

Correlation effects mainly on Ni d band

d-wave superconductivity is the lowest energy state

Static magnetism is absent near optimal doping

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.