题目：Orbital Selective Interaction in V₂Se₂O and Altermagnetic Order in its Full Electron Doping Case KV₂Se₂O

报告人：翁红明 研究员，中国科学院物理研究所

时间：2025年12月18日（周四）下午15:00

地点：国家脉冲强磁场科学中心B206

报告摘要：

Orbital-selective many-body effects, in which electrons occupying different orbitals experience distinct interaction strengths, play a crucial role in correlated multiorbital materials. However, these effects usually manifest in a complex manner, obscuring their microscopic origins. Here, by combining angle-resolved photoemission spectroscopy measurements with theoretical calculations, we reveal pronounced orbital selectivity in both electron-electron correlation and electron-phonon coupling in the van der Waals material V₂Se₂O. Electron-electron correlation induces distinct bandwidth renormalization exclusively in the V d_xy-derived band. On the other hand, the d_xz/yz-derived band exhibits a sharp kink anomaly, arising from enhanced coupling to high-energy phonon modes dominated by oxygen vibrations. Thus, V₂Se₂O is a paramagnetic metal with pronounced orbital selective electron-electron and electron-phonon interactions. Due to the layered structure, K can be intercalated into V₂Se₂O for electron doping and KV₂Se₂O is of full doping case. Instead of paramagnetic, through comprehensive characterization and calculation, KV₂Se₂O is unambiguously identified as a metallic room-temperature altermaget with d-wave spin-momentum locking. The highly anisotropic spin-polarized Fermi surfaces and the spin-density-wave order emerging in the altermagnetic phase make it an extraordinary platform for high-performance spintronic devices and studying many-body effects coupled with the unconventional magnetism and magnetic fluctuations tuned by carrier concentration.

报告人简介：

翁红明，中国科学院物理研究所研究员、博士生导师，中国科学院凝聚态物质科学数据中心主任。本科、硕士、博士均就读于南京大学物理学系，先后在日本东北大学、北陆先端科学技术大学院大学等任博士后和助理教授，2010年回国工作。主要从事计算凝聚态物理研究，并致力于建设凝聚态物质科学数据体系和数智驱动的物质研究新范式等。迄今共发表论文290多篇，被引用32000多次。计算预言并与实验合作发现首个外尔半金属TaAs的工作入选英国物理学会（IOP）2015年物理世界十大突破、美国物理学会（APS）2015年八大亮点工作。曾获国家自然科学奖一等奖（3/5）、陈嘉庚科学奖（3/3）、日本仁科亚洲奖、科学探索奖、科睿唯安“高被引科学家”（2018年-2025年）、中国科学十大进展（2015年、2017年）等。主持国家重点研发计划，国家杰青等项目，担任npj Computational Materials期刊副主编、亚洲青年科学家奖（Asian Young Scientist Fellowship）物质科学分会评审委员等。