ニッケル酸化物高温超伝導体の機構解明につながる重要証拠を発見 （Chinese Scientists Discover Key Evidence for Mechanism Behind Nickelate High-temperature Superconductors）

2026-05-22 中国科学技術大学（USTC）

＜関連情報＞

• http://en.ustc.edu.cn/info/1007/5176.htm
• https://www.science.org/doi/10.1126/science.adw8329

( La ,Pr,Sm)3Ni2O7薄膜におけるノードレス超伝導ギャップと電子-ボソン結合 Nodules superconducting gap and electron-boson coupling in (La,Pr,Sm)3Ni2O7 films

Jianchang Shen, Guangdi Zhou, Yu Miao, Peng Li, […] , and Zhuoyu Chen
Science  Published:21 May 2026
DOI:https://doi.org/10.1126/science.adw8329

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.