报告题目：Enhanced Unconventional Superconductivity in Doped Samarium Infinite-layer Nickelates

报 告 人：李丹枫，香港城市大学

报告时间：2025年6月6日（周五）下午14:00

报告地点：物理楼W318

内容摘要: Since the discovery of superconductivity in infinite-layer nickelates, these materials have emerged as a promising platform for understanding unconventional superconductivity beyond cuprates, though synthesis challenges have largely limited progress to early lanthanide compounds. In this talk, I will present our synthesis and characterisation of phase-pure superconducting samarium-based infinite-layer nickelate thin films [1], including the first demonstration of Sm_1-xSr_xNiO₂ and co-doped variants with europium and calcium. These epitaxial films achieve superconducting transition temperatures up to 32.5 K and reveal a hybrid mixture of 2D and 3D superconductivity through enhanced rare-earth 5d and Ni 3d orbital coupling, with europium doping driving the system toward 3D behaviour and distinctive negative magnetoresistance. These findings provide clear design principles for achieving higher transition temperatures through strategic rare-earth site engineering. Recent developments in this rapidly evolving field will also be shared.

参考文献:

[1] M. Yang, H. Wang, J. Tang, J. Luo, X. Wu, R. Mao, W. Xu, G. Zhou, Z. Dong, B. Feng, L. Shi, Z. Pei, P. Gao, Z. Chen, D. F. Li, Enhanced superconductivity in co-doped infinite-layer samarium nickelate thin films, arXiv:2503.18346 (2025).

报告人简介：李丹枫，香港城市大学物理系长聘副教授，理学院副院长（科研与研究生教育），博士生导师。主要从事新型氧化物电子薄膜制备、原子尺度异质结外延生长、低维超导体系及界面新奇物理性质等相关研究。2019年，他与斯坦福大学Harold Hwang教授领导的研究小组在世界上首次发现镍基超导材料，引发镍基超导材料研究热潮。获得2024年度氧化物电子学杰出研究奖，2023年度亚太物理联合会-亚太理论物理中心杨振宁奖，入选2021年度麻省理工科技评论35岁以下创新者35人（中国）榜单。