Electronic structure and correlations in planar trilayer nickelate Pr ₄ Ni ₃ O ₈

Abstract

The discovery of superconductivity in planar nickelates raises the question of how the electronic structure and correlations of Ni 1+ compounds compare to those of the Cu 2+ cuprate superconductors. Here, we present an angle-resolved photoemission spectroscopy (ARPES) study of the trilayer nickelate Pr 4 Ni 3 O 8 , 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.

Limits to the strain engineering of layered square-planar nickelate thin films

“…surface 23 , charge/spin stripes 24,25 , orbital polarization 12 , and large superexchange 26,27 . Layered square-planar nickelate thin films thus form an exciting platform to investigate the role of dimensionality, epitaxial strain, and chemical doping in nickelate superconductivity.…”

The Quest for High-Temperature Superconductivity in Nickelates under Ambient Pressure

“…One possibility is that this is related to the known DFT's inability to adequately describe the ground state of strongly correlated electron materials, of which nickelates and cuprates are prime examples-e.g., DFT predicts La 2 CuO 4 to be metallic, while, experimentally, it is an antiferromagnetic insulator. In nickelates, some relevant electron energy bands near the Fermi level are strongly renormalized; the DFT bands are as much as 500-800% wider than the bands measured by ARPES experiments [26][27][28]. Rhodes and Wahl have argued that the chemistry and crystal structure are usually controlled by the electron spectrum and states at higher (few eV) energy scales and that DFT adequately describes these [18].…”

Recent progress in angle-resolved photoemission spectroscopy

“…Today, after nearly 40 years, the field remains quite active. Recent important results include studies of one-dimensional cuprate chains [515], and other families of high-temperature superconductors such as nickelates [516], manganites [517], and iron-based compounds [518][519][520].…”