Electronic structure and correlations in planar trilayer nickelate Pr4Ni3O8

The discovery of superconductivity in planar nickelates raises the question of how the electronic structure and correlations of 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 a Fermi surface resembling that of the hole-doped cuprates but with 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 cuprate interactions are somewhat less local. Nevertheless, the nickelates still demonstrate the strange-metal behavior in the electron scattering rates. Understanding the similarities and differences between these two families of strongly correlated superconductors is an important challenge.

Automated summary

This article introduces the discovery of superconductivity in planar nickelates and explores the differences in electronic structure and correlations between Ni1+ compounds and Cu2+ cuprate superconductors. An ARPES study of the trilayer nickelate Pr4Ni3O8 reveals a Fermi surface resembling that of the hole-doped cuprates but with critical differences. The electronic correlations in the nickelates are about twice as strong as in the cuprates and are almost k-independent, indicating a likely origin from a local effect, such as the Mott interaction, whereas cuprate interactions are somewhat less local. Nevertheless, the nickelates still demonstrate strange-metal behavior in electron scattering rates. Understanding the similarities and differences between these two families of strongly correlated superconductors is an important challenge.