Electronic structure of superconducting nickelates probed by resonant photoemission spectroscopy

POSTER

Abstract

The discovery of infinite-layer nickelate superconductors has spurred enormous interest. While the Ni1+ cations possess nominally the same 3d9 configuration as Cu2+ in high-TC cuprates, the electronic structure consistencies and variances remain elusive, due to the lack of direct experimental probes. Here, we present a soft x-ray photoemission spectroscopy study on both parent and doped infinite-layer Pr-nickelate thin films with a doped perovskite reference. By identifying the Ni character with resonant photoemission and comparison to density function theory + U calculations, we estimate U ~ 5 eV, smaller than the charge transfer energy △ ~ 8 eV, in contrast to the cuprates being charge transfer insulators. Near the Fermi level, we observe a signature of rare-earth spectral intensity in the parent compound, which is depleted upon doping. Our results demonstrate a complex interplay between the strongly correlated Ni 3d and the weakly-interacting rare-earth 5d states for the superconductivity in the nickelates.

*The work at SLAC and Stanford was supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Materials Sciences and Engineering (contract No. DE-AC02-76SF00515) and the Gordon and Betty Moore Foundation's Emergent Phenomena in Quantum Systems Initiative (grant No. GBMF9072, synthesis equipment). This research used resources of the Advanced Photon Source, a DOE user facility operated by Argonne National Laboratory under contract No. DE-AC02-06CH11357. The work at LBNL was supported by US DOE under contract No. DE-AC02-05CH11231.

Publication: arXiv:2106.03963

Presenters

  • Zhuoyu Chen

    • Stanford University
    • Stanford Univ

Authors

  • Zhuoyu Chen

    • Stanford University
    • Stanford Univ

  • Motoki Osada

    • Stanford Univ
    • Stanford University; SLAC National Accelerator Laboratory
    • Stanford University

  • Danfeng Li

    • Stanford Univ
    • City University of Hong Kong
    • Stanford University

  • Emily M Been

    • Stanford University

  • Sudi Chen

    • Stanford Univ
    • Stanford University

  • Makoto Hashimoto

    • SLAC National Accelerator Laboratory
    • SLAC - Natl Accelerator Lab
    • SLAC National Accelerator Lab

  • Donghui Lu

    • SLAC - Natl Accelerator Lab
    • SLAC National Accelerator Laboratory
    • SLAC National Accelerator Lab

  • Sung-Kwan Mo

    • Lawrence Berkeley National Laboratory

  • Kyuho Lee

    • Stanford University
    • Stanford University; SLAC National Accelerator Laboratory

  • Bai Yang Wang

    • Stanford University
    • Stanford Univ
    • Stanford University; SLAC National Accelerator Laboratory

  • Fanny Rodolakis

    • Advanced Photon Source, Argonne National Laboratory
    • Argonne National Laboratory

  • Jessica L McChesney

    • Argonne National Laboratory

  • Chunjing Jia

    • SLAC - Natl Accelerator Lab
    • Stanford University; SLAC National Accelerator Laboratory
    • SLAC National Accelerator Lab

  • Brian Moritz

    • SLAC National Accelerator Laboratory & S
    • SLAC - Natl Accelerator Lab
    • SLAC National Accelerator Lab
    • SLAC National Accelerator Laboratory & Stanford University
    • SLAC National Accelerator Laboratory

  • Thomas P Devereaux

    • Stanford Univ
    • Stanford University; SLAC National Accelerator Laboratory
    • Stanford University

  • Harold Y Hwang

    • Stanford Univ
    • Stanford University; SLAC National Accelerator Laboratory
    • Stanford University

  • Zhixun Shen

    • Stanford University
    • Geballe Laboratory for Advanced Materials, Stanford University, USA
    • Stanford Univ