Nodeless superconducting gap and electron-boson coupling in (La,Pr,Sm) 3 Ni 2 O 7 films

作者：Jianchang Shen, Guangdi Zhou, Miao Yu, Liming Peng, Zhipeng Ou, Yaqi Chen, Zechao Wang, Runqing Luan, Huizhu Sun, Zikun Feng, Xinru Yong, Yueying Li, Lizhi Xu, Wei Lv, Zihao Nie, Heng Wang, Haoliang Huang, Yujie Sun, Qi Xue, Junfeng He, Zhuoyu Chen · 发表于：Science · 年份：2026 · DOI：10.1126/science.adw8329 · 被引用次数：4 · 研究领域：Magnetic and transport properties of perovskites and related materials、Physics of Superconductivity and Magnetism、Iron-based superconductors research

The discovery of superconductivity in Ruddlesden-Popper 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 ultrahigh-vacuum cryogenic sample quenching and transfer technique. A superconducting gap of ~18 milli–electron volts 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 milli–electron volts below the 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 Ruddlesden-Popper bilayer nickelates.