Electronic Structure of Compressively Strained Bilayer Nickelate Thin Film
5 affiliations
- 1SLAC National Accelerator Laboratory
- 2Stanford University
- 3University of Florida
- 4Max Planck Institute for Chemical Physics of Solids
- 5Stanford Synchrotron Radiation Lightsource
Abstract
The discovery of superconductivity in bulk bilayer nickelates under high pressure, and its subsequent stabilization in compressively strained thin films at ambient pressure, has established a new platform for exploring high- T c superconductivity beyond the cuprates. Central to this development is the prominent role of the 3 d z 2 orbital in shaping the low-energy electronic structure, imposing constraints on microscopic theories and fueling debate over the superconducting mechanism. Here we report a systematic angle-resolved photoemission spectroscopy study of compressively strained bilayer nickelate thin films spanning Ca doping, oxygen stoichiometry and film thickness. Despite variations in oxygen-vacancy disorder and surface termination, the electronic structure remains robust and exhibits a systematic strain-driven evolution consistent with an intermediate-correlation regime. In particular, we demonstrate a Ca-doping-induced electronic structure evolution that is consistent with Fermi-level crossing of the γ band and is decoupled from the presence of superconductivity, suggesting that, while important for the γ band to be near the Fermi level, the debated γ crossing and the resulting Fermi pocket may not be a prerequisite for superconductivity. Together, our results establish key spectroscopic constraints on the minimal fermiology and correlation strength relevant to superconductivity in bilayer nickelates, providing an experimental foundation for microscopic theories of their pairing mechanism.
Related
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- Spectroscopic evidence of competing diagonal spin interactions and spin disproportionation in the bilayer nickelate La 3 Ni 2 O 7
- Observation of superconductivity-induced leading-edge gap in a bilayer nickelate
BibTeX
@article{wang2026electronic,
title = {{Electronic Structure of Compressively Strained Bilayer Nickelate Thin Film}},
author = {Bai Yang Wang and Sebastien N. Abadi and Yidi Liu and Yu Zhang and Yong Zhong and Yijun Yu and Berit Hansen Goodge and Xiaoliang Zhang and Yiming Wu and Ruohan Wang and Jiarui Li and Yaoju Tarn and Eun Kyo Ko and Vivek Thampy and Chun Lin and Makoto Hashimoto and Dong-Hui Lu and Young S. Lee and Thomas Devereaux and Chunjing Jia and Harold Y. Hwang and Zhi‐Xun Shen},
journal = {Physical Review X},
year = {2026},
month = jun,
doi = {10.1103/4h5x-btvx},
url = {https://doi.org/10.1103/4h5x-btvx},
note = {CC BY},
}
RIS
TY - JOUR
TI - Electronic Structure of Compressively Strained Bilayer Nickelate Thin Film
AU - Bai Yang Wang
AU - Sebastien N. Abadi
AU - Yidi Liu
AU - Yu Zhang
AU - Yong Zhong
AU - Yijun Yu
AU - Berit Hansen Goodge
AU - Xiaoliang Zhang
AU - Yiming Wu
AU - Ruohan Wang
AU - Jiarui Li
AU - Yaoju Tarn
AU - Eun Kyo Ko
AU - Vivek Thampy
AU - Chun Lin
AU - Makoto Hashimoto
AU - Dong-Hui Lu
AU - Young S. Lee
AU - Thomas Devereaux
AU - Chunjing Jia
AU - Harold Y. Hwang
AU - Zhi‐Xun Shen
PY - 2026
DA - 2026/06/17
JO - Physical Review X
DO - 10.1103/4h5x-btvx
UR - https://doi.org/10.1103/4h5x-btvx
AB - The discovery of superconductivity in bulk bilayer nickelates under high pressure, and its subsequent stabilization in compressively strained thin films at ambient pressure, has established a new platform for exploring high- T c superconductivity beyond the cuprates. Central to this development is the prominent role of the 3 d z 2 orbital in shaping the low-energy electronic structure, imposing constraints on microscopic theories and fueling debate over the superconducting mechanism. Here we report a systematic angle-resolved photoemission spectroscopy study of compressively strained bilayer nickelate thin films spanning Ca doping, oxygen stoichiometry and film thickness. Despite variations in oxygen-vacancy disorder and surface termination, the electronic structure remains robust and exhibits a systematic strain-driven evolution consistent with an intermediate-correlation regime. In particular, we demonstrate a Ca-doping-induced electronic structure evolution that is consistent with Fermi-level crossing of the γ band and is decoupled from the presence of superconductivity, suggesting that, while important for the γ band to be near the Fermi level, the debated γ crossing and the resulting Fermi pocket may not be a prerequisite for superconductivity. Together, our results establish key spectroscopic constraints on the minimal fermiology and correlation strength relevant to superconductivity in bilayer nickelates, providing an experimental foundation for microscopic theories of their pairing mechanism.
SN - 2160-3308
ER -