近日，南方科技大学陈卓昱团队报道了（La,Pr,Sm）3Ni2O7薄膜中的无节点超导隙和电子-玻色子耦合。相关论文于2026年5月21日发表在《科学》杂志上。
学界在常压下发现Ruddlesden-Popper（RP）结构双层镍酸盐薄膜的超导电性，为直接研究超导态的电子能标及配对机制提供了契机。
研究组通过开发一种超高真空低温样品淬冷及传递技术，对超导态（La,Pr,Sm）3Ni2O7薄膜进行了角分辨光电子能谱测量。结果发现，沿布里渊区对角线方向存在一个具有相干峰、约18 meV的超导能隙。该有限能隙遍布整个布里渊区，表明不存在能隙节点。在费米能级以下约70 meV处，观测到能量-动量色散关系中出现一个扭结，指示着电子-玻色子耦合的存在。无节点超导能隙与电子-玻色子耦合的同时观测，为理解RP结构双层镍酸盐中的配对对称性及胶合机制提供了深刻见解。
附：英文原文
Title: Nodeless superconducting gap and electron-boson coupling in (La,Pr,Sm)3Ni2O7 films
Author: Jianchang Shen, Guangdi Zhou, Yu Miao, Peng Li, Zhipeng Ou, Yaqi Chen, Zechao Wang, Runqing Luan, Hongxu Sun, Zikun Feng, Xinru Yong, Yueying Li, Lizhi Xu, Wei Lv, Zihao Nie, Heng Wang, Haoliang Huang, Yu-Jie Sun, Qi-Kun Xue, Junfeng He, Zhuoyu Chen
Issue&Volume: 2026-05-21
Abstract: 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)3Ni2O7 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.
DOI: adw8329
Source: https://www.science.org/doi/10.1126/science.adw8329