Many-Body Trends of Reduced Ruddlesden-Popper Nickelates

In this chapter, we expand on our results of Chaps. 3 and 4 and obtain many-body trends for the electronic structure of the entire series of reduced Ruddlesden-Popper nickelates \(n=2\text{--}6\) , \(\infty \) including interactions within DMFT at full charge self-consistency. We find that many features of the electronic structure are common to the entire nickelate series, namely, strongly correlated Ni- \(d_{x^{2}-y^{2}}\) orbitals that dominate the low-energy physics, mixed Mott-Hubbard/charge-transfer characteristics, and R(5d) orbitals acting as charge reservoirs. Interestingly, we uncover that the electronic structure of the layered nickelates is highly tunable as the dimensionality changes from quasi-two-dimensional to three-dimensional as \(n \rightarrow \infty \) . Specifically, we identify the tunable electronic features to be: the charge-transfer energy, presence of \(R(5d)\) states around the Fermi level, and the strength of electronic correlations. This chapter is based on results published in Phys. Rev. B 106, 115132 (2022) .