铀基化合物UTmGa5（Tm=Fe,Co,Ni,Pd,Pt）中5f电子特性研究

铀基化合物具有丰富而奇异的量子现象，如重费米子态、非常规超导、非费米液体行为、磁有序、隐藏序等。5f电子的局域-巡游双重特性是理解上述各种奇异量子现象的关键因素，对深刻理解铀、钚等核材料的复杂宏观物性也具有借鉴和指导意义。铀基115化合物具有与铈基115以及钚基115化合物相同的晶体结构，但显著差异的基态性质。本项目拟采用角分辨光电子能谱仪、扫描隧道显微镜/扫描隧道谱，结合理论计算对UTmGa5（Tm=Fe、Co、Ni、Pd和Pt）这几种典型铀基115化合物中5f电子在反铁磁转变、高低温局域-巡游转变前后的基本特性进行研究，并通过与Ce基115化合物中4f电子特性的比较，深入理解5f与4f电子特性的差异，以及f电子与导带电子相互作用强度的微小变化如何决定体系的基态性质。

Uranium-based compounds possess various exotic quantum phenomena, including heavy-fermion state, unconventional superconductivity, non-Fermi-liquid behavior, magnetic order, and hidden order. The localized-itinerant dual character of 5f electrons is the key to understanding these phenomena, and also of instructive and directive significance to provide a deep insight into the complex physical properties of U- and Pu- based nuclear materials. U-based 115 compounds have the same crystal structure as the Ce-based 115 and Pu-based 115 compounds, but with significantly different ground state properties. This project aims to study the characters of the 5f electrons during the antiferromagnetic and localized-to-itinerant transition, by using angle-resolved photoemission spectroscopy, scanning tunneling spectroscopy and theoretical calculations. By comparing with the 4f electron character in Ce-115 compounds, we can understand the difference between 4f and 5f electrons, and how subtle changes in the interaction of f electrons with conduction electrons determine their ground state properties.