高磁場下ニッケル酸化物で再入超伝導を発見 (Researchers Discover High-Field Re-entrant Superconductivity in Nickelates under High Magnetic Fields)

2026-05-11 合肥物質科学研究院（HFIPS）

Extreme low-temperature rotational electrical transport test results under the 45 T hybrid magnet: Normalized resistance curves of highly Eu-doped SCE_0.38 and SCE_0.40 samples at a base temperature of 0.3 K under various magnetic field angles.(Image by MENG Wenjie)

＜関連情報＞

• https://english.hf.cas.cn/nr/rn/202605/t20260511_1159119.html
• https://www.nature.com/articles/s41586-026-10547-y

Euドープ無限層ニッケル酸塩における磁場再突入型超伝導 Field re-entrant superconductivity in Eu-doped infinite-layer nickelates

Mingwei Yang,Jiayin Tang,Xianfeng Wu,Heng Wang,Wenjing Xu,Haoliang Huang,Zhicheng Pei,Wenjie Meng,Guangli Kuang,Ming Yang,Jinfeng Xu,Sixia Hu,Junfeng Wang,Liang Li,Ze Wang,Chuanying Xi,Li Pi,Qingyou Lu,Ziqiang Wang,Qikun Xue,Zhuoyu Chen & Danfeng Li
Nature  Published:23 April 2026
DOI:https://doi.org/10.1038/s41586-026-10547-y  Unedited version

Abstract

Intertwined superconducting and magnetic orders may give rise to exotic quantum phases^1–7, including field-induced and re-entrant superconductivity^8–10. However, such magnetism-enhanced superconductivity has remained elusive in superconductors with higher transition temperatures^1–3. While infinite-layer nickelates represent a new class of unconventional superconductors^11–20, the impact of rare-earth magnetism on superconducting properties remains largely unexplored. Here, we show that Eu-doped infinite-layer nickelate Sm_0.95−xCa_0.05Eu_xNiO₂ exhibits a magnetic-field-induced re-entrant superconducting phase in the Eu-rich over-doped regime. Zero-resistance transport and high-field diamagnetic screening confirm the superconducting nature of this phase, which emerges after the initial suppression of low-field superconductivity and remains robust across a broad range of temperatures, fields and field orientations. In the same doping range, we observe nonlinear Hall transport and hysteretic magnetoresistance, indicating the unconventional nature of the re-entrant behaviour. While partially consistent with a compensation mechanism between the Eu-derived exchange field and the applied field, our data reveal pronounced deviations from this model at the highest-doping levels. Our findings establish infinite-layer nickelates as a fertile platform for exploring magnetically driven high-field superconductivity in strongly correlated oxides.