表面吸附铀原子及其人工纳米结构的近藤效应研究

项目名称： 表面吸附铀原子及其人工纳米结构的近藤效应研究

项目编号： No.11304291

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 冯卫

作者单位： 中国工程物理研究院

项目金额： 25万元

中文摘要： 表面吸附磁性原子近藤效应的扫描隧道显微学研究是活跃在凝聚态物理和表面物理中一个重要研究课题，但是目前的研究工作大多局限在磁性原子为3d过渡元素原子，而对表面吸附磁性原子为具有f局域磁矩尤其是5f局域磁矩原子的研究很少，缺乏对其自旋态和近藤效应的认识与理解。本申请项目拟通过在超高真空中制备分散吸附在不同一价贵金属表面的具有5f局域磁矩的单个铀原子，利用超高真空低温扫描隧道显微镜的超高空间和能量分辨、强大的谱学分析，并结合第一性原理的理论计算和模拟，研究表面吸附单个铀原子近藤效应的表象与机制，探索不同的吸附位、最近邻原子数改变、衬底表面态调制等因素对铀原子近藤效应的影响；利用原子操纵技术构造不同的人工纳米结构，研究表面吸附铀原子间的磁相互作用，并理解由5f局域磁矩构成的两杂质近藤问题。

中文关键词： 铀原子；近藤效应；原子轨道；扫描隧道显微镜；扫描隧道谱

英文摘要： Scanning tunneling microscopy (STM) study of the Kondo effect of the magnetic atoms adsorbed on surfaces is an active and important research topic in condensed matter physics and surface physics. Until now, the past works were mostly concentrated on the study of magnetic atoms with magnetic moment originated from unpaired spin of 3d electrons, but there were few researches about the adsorbed magnetic atoms with magnetic moment originated from unpaired spin of f electrons especially 5f electrons, and it was very lacking of knowledge and understanding about the spin states and Kondo effect of actinide atoms adsorbed on surfaces. This project we applied plans to prepare samples with individual U atoms adsorbed on different simple noble metal surfaces, such as Cu, Ag and Au. By the using of ultra-high-vacuum and low-temperature STM, taking advantage of the ultra-high spatial and energy resolution, and powerful scanning tunneling spectroscopy (STS) analysis of STM, and combining with the first-principles calculations and simulations, we are going to research the appearance and mechanisms of the Kondo effect of individual uranium adatoms, and research the Kondo effect of individual U adatoms affected by different adsorption sites, the number of nearest neighbor atoms, modulation of the surface state, and so on. By the

英文关键词： uranium atom；Kondo effect；atomic orbital；STM；STS