反铁磁铀基化合物USb2的5f电子奇异特性研究

项目名称： 反铁磁铀基化合物USb2的5f电子奇异特性研究

项目编号： No.11504341

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 谭世勇

作者单位： 中国工程物理研究院

项目金额： 24万元

中文摘要： 铀基化合物由于具有关联性较强的5f电子而呈现出纷繁复杂的宏观物理现象。由于实验数据的匮乏，理论模拟的困难，目前人们对5f电子的理解还远远不够。5f电子结构在各种有序度下的具体表现以及在相变过程中的演化规律，还没有被充分研究和揭示。本课题选择反铁磁铀基化合物USb2为研究对象，拟采用助溶剂方法生长高质量的USb2单晶材料，利用PPMS测量其宏观输运性质，采用角分辨光电子能谱和扫描隧道显微镜两种先进的电子结构测量技术，并结合理论计算对5f电子的各种奇异行为和多自由度耦合现象进行系统、深入的研究。探索铀基化合物5f电子在反铁磁相变、局域-巡游转变前后的基本特征，多自由度耦合的一般规律和物理机制以及其在电子结构上的具体表现。我们的研究结果有望揭示5f电子的某些普适行为特征，为理解5f电子材料的各种奇异特性提供重要的实验数据支撑。

中文关键词： 铀基化合物；反铁磁相变；强关联电子；电子结构

英文摘要： Uranium compounds present a plethora of exotic physical behaviors due to the many-body interactions of 5f electrons. The nature of 5f electrons are far from being thoroughly understood due to lack of experimental data and the difficultly in dealing with the strong interactions in f-electron systems. The specific behavior of the 5f states in different collective ordering states and the electronic structure evolution during such phase transitions have not been well studied and revealed. Our proposed project main focus on the study of the 5f electronic states in the antiferromagnetic uranium compound USb2.High quality single crystals will we grown by flux method, the transport properties will be studied using PPMS to reveal the macro transport characters. The 5f electronic structure will be studied using angle resolved photoemission spectroscopy and scanning tunneling spectroscopy combined with first principle calculations. The exotic properties of the 5f states and the coupling between different degrees of freedom will be studied systematically and comprehensively. We will explore the specific representation of the 5f states before and after the antiferromagnetic transition and the localized to itinerant electronic transition. The common rule of the coupling between different degrees of freedom and its representation in band structures will also be studied. Our research results will provide important information to explain the exotic properties of 5f electron materials and may shed light on the understanding of the universal nature of 5f states.

英文关键词： uranium compound;antiferromagnetic transition;strong correlated electrons;electronic structure