Nodeless superconducting gap and electron-boson coupling in (La,Pr,Sm) <sub>3</sub> Ni <sub>2</sub> O <sub>7</sub> films
The discovery of superconductivity in Ruddlesden-Popper (RP) bilayer nickelate films under ambient pressure provides an opportunity to directly investigate electronic energy scales of the superconducting state and the pairing mechanism. We report angle-resolved photoemission spectroscopy measurements of superconducting (La,Pr,Sm) 3 Ni 2 O 7 thin films by developing an ultra-high vacuum cryogenic sample quenching and transfer technique. A superconducting gap of ~18 meV with coherence peaks is observed along the Brillouin zone diagonal. The finite gap persists across the entire Brillouin zone, revealing the absence of gap nodes. A kink is observed in the energy-momentum dispersion at ~70 meV below Fermi level, indicating an electron-boson coupling. The simultaneous observation of a nodeless superconducting gap and electron-boson coupling provides insight into the pairing symmetry and gluing mechanism in RP bilayer nickelates.
Authors
- Lizhi Xu (ORCID: https://orcid.org/0000-0001-6888-0524)
- Y Li
- Yaqi Chen (ORCID: https://orcid.org/0000-0002-1472-2624)
- Jianchang Shen (ORCID: https://orcid.org/0000-0002-7446-9114)
- Peng Li (ORCID: https://orcid.org/0000-0003-3497-1887)
- Zihao Nie
- Guangdi Zhou (ORCID: https://orcid.org/0000-0002-9378-1699)
- Han Sun (ORCID: https://orcid.org/0000-0002-7850-9574)
- Junfeng He
- H Wang
- Zechao Wang (ORCID: https://orcid.org/0000-0002-3265-7344)
- Runqing Luan
- Yu Miao
- Haoliang Huang (ORCID: https://orcid.org/0000-0002-5686-5519)
- Zhuoyu Chen (ORCID: https://orcid.org/0000-0002-6111-7558)
- Zhipeng Ou (ORCID: https://orcid.org/0009-0002-0681-4665)
- Wei Lv
- Xinru Yong
- Zikun Feng
- Yu-Jie Sun (ORCID: https://orcid.org/0000-0003-1782-8405)
- Qi-Kun Xue (ORCID: https://orcid.org/0009-0001-7377-8337)
Institutions
- University of Science and Technology of China (CN)
- Southern University of Science and Technology (CN)
- Hefei National Center for Physical Sciences at Nanoscale (CN)
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (CN)
- Tsinghua University (CN)
Publication Details
- Journal
- Science
- Published
- 2026-05-21
- DOI
- https://doi.org/10.1126/science.adw8329
- Primary Topic
- Magnetic and transport properties of perovskites and related materials
- Type
- article
- Field-Weighted Citation Impact
- 0.00