Electronic structure of higher-order Ruddlesden-Popper nickelates

TL;DR

This study uses first-principles calculations to analyze the electronic structure of higher-order Ruddlesden-Popper nickelates, revealing similarities to cuprates and potential for tuning electronic properties through dimensionality.

Contribution

It provides a detailed electronic structure analysis of La$_{n+1}$Ni$_n$O$_{3n+1}$ nickelates for $n=4-6$, highlighting their similarities to cuprates and the impact of dimensionality.

Findings

Large holelike Fermi surfaces with $d_{x^2-y^2}$ character similar to cuprates

Appearance of $d_{z^2}$ bands at higher $n$ values

Potential to modify electronic ground states by tuning dimensionality

Abstract

We analyze the electronic structure of the recently synthesized higher-order nickelate Ruddlesden-Popper phases La$_{n+1}$Ni$_n$O$_{3n+1}$ ($n=4-6$) using first-principles calculations. For all materials, our results show large holelike Fermi surfaces with $d_{x^2-y^2}$ character that closely resemble those of optimally hole-doped cuprates. For higher values of $n$, extra non-cuprate-like bands of $d_{z^2}$ orbital character appear. These aspects highlight that this Ruddlesden-Popper series can provide a means to modify the electronic ground states of nickelates by tuning their dimensionality. With their similarities and differences to the cuprates, this new family of materials can potentially shed light on the physics of copper-based oxides.