Electronic structure and correlations in planar trilayer nickelate Pr4Ni3O8

TL;DR

This study uses ARPES to analyze the electronic structure of trilayer nickelate Pr4Ni3O8, revealing similarities to cuprates but with stronger, more local electronic correlations, advancing understanding of nickelate superconductors.

Contribution

It provides the first detailed ARPES characterization of Pr4Ni3O8, highlighting its electronic similarities to cuprates and identifying the nature and strength of correlations in nickelates.

Findings

Fermi surface similar to hole-doped cuprates

Electronic correlations are about twice as strong as in cuprates

Correlations are predominantly local, likely Mott interactions

Abstract

The recent discovery of superconductivity in hole-doped planar nickelates R1-xSrNiO2 (R=Pr,Nd) raises the foundational question of how the electronic structure and electronic correlations of these Ni1+ compounds compare to those of the Cu2+ cuprate superconductors. Here, we present an Angle-Resolved Photoemission Spectroscopy (ARPES) study of the trilayer nickelate Pr4Ni3O8, revealing an electronic structure and Fermi surface very similar to that of the hole-doped cuprates but with a few critical differences. Specifically, the main portions of the Fermi surface are extremely similar to that of the bilayer cuprates, with an additional piece that can accommodate additional hole doping. We find that the electronic correlations are about twice as strong in the nickelates and are almost k-independent, indicating that they originate from a local effect-likely the Mott interaction, whereas the cuprate interactions are somewhat less local. Nevertheless, the nickelates still demonstrate an approximately linear in energy and linear in temperature scattering rate. Understanding the similarities and differences between these two related families of strongly-correlated novel superconductors is an important challenge.