Planar nickelates share the similar crystal structure and 3d electron configuration with high T_C cuprate materials, and thus can be considered as a potential proxy for cuprate physics as well as a possible candidate for hosting high-temperature superconductivity. A previous study has shown that Pr₄Ni₃O₈, a metallic material in the planar nickelate family, has a pronounced orbital character of dx²-y²near the Fermi energy [1], which is a signature of the cuprate electronic structure. Here we present the first angle-resolved photoemission spectroscopy study of Pr₄Ni₃O₈. Consistent with the electron counting, planar nickelate Pr₄Ni₃O₈ shows a non-gapped Fermi surface that resembles the one in the heavily over-doped cuprate. A detailed comparison of the ARPES result shows more similarity in the electronic structure. Our observations demonstrate that planar nickelate Pr₄Ni₃O₈ material can be a potential test ground for the study of cuprate physics.


[1] Junjie Zhang et al. Large orbital polarization in a metallic square-planar nickelate. Nat. Phys.13, 864–869 (2017).