报告题目：压力下液氮温区镍氧化物超导体的发现

报告人：王猛教授    中山大学

报告时间：2024年03月14日（周四）10:00

报告地点：理六栋302        邀请人：周涛

报告内容：

High-transition-temperature (high-Tc) superconductivity in cuprates has been discovered for more than three decades, but the underlying mechanism remains a mystery. Cuprates are the only unconventional superconducting family that hosts bulk superconductivity with Tcs above the liquid nitrogen boiling temperature at 77 Kelvin. We found superconductivity in single crystals of La3Ni2O7 grown by the high-pressure floating zone method with a maximum Tc of 80 K at pressures between 14.0-43.5 gigapascals. Our collaborators have confirmed the high Tc superconductivity on our samples independently. The superconducting phase under high pressure exhibits an orthorhombic structure of Fmmm space group with the 3dx2-y2 and 3dz2 orbitals of Ni cations strongly mixing with oxygen 2p orbitals. Density functional theory calculations suggest the superconductivity emerges coincidently with the metallization of the σ-bonding bands under the Fermi level, consisting of the 3dz2 orbitals with the apical oxygens connecting Ni-O bilayers. ARPES and infrared measurements are consistent with our theoretical expectation. Thus, the discoveries not only reveal important clues for the high-Tc superconductivity in this Ruddlesden-Popper double-layered perovskite nickelates but also provide a new family of compounds to investigate the high-Tc superconductivity mechanism. Indeed, La4Ni3O10 has also been found superconductivity below 20 K under pressure. The new progresses in the studies of nickelate high Tc superconductors will be introduced.

专家简介：

中山大学物理学院教授、博士生导师，现任中山大学物理学院副院长、广东省磁电物性分析与器件重点实验室副主任、物理学院中子科学与技术中心主任。王猛教授本科毕业于吉林大学物理学院，博士毕业于中国科学院物理研究所超导国家重点实验室，之后在加州大学伯克利分校物理系开展博士后研究工作。王猛教授已发表论文80余篇，包括Nature、Nature Physics、Nature Communications、Physical Review Letters、Physical Review B等杂志，是Science China-PMA杂志青年编委，长期担任Nature、Nature Physics、Physical Review Letters等杂志审稿人，成果入选“两院院士评选2023年中国十大科技进展新闻”、“2023年中国重大科学、技术和工程进展”。王猛教授研究兴趣包括非常规超导材料和量子磁性材料的物性及机理研究，研究方法包括材料生长、中子散射、高压技术等，推动并参与中国首台高能非弹性中子散射飞行时间谱仪建设。