The electronic structure and related physical properties of correlated electron systems

相关电子系统的电子结构和相关物理性质

• 批准号: 250040-2013
• 负责人: Sawatzky, George
• 金额: $ 5.17万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633493
• 关键词: electronic; structure; related; physical; properties

Strongly correlated electron systems exhibit some of the most interesting physical properties important for present and future applications in electronic devices, sustainable energy, biomedical devices, transportation and perhaps even quantum computing. Materials made of transition metal and rare earth compounds such as their oxides are examples often exhibiting extreme properties such as high temperature superconductivity, high thermoelectric power, high dielectric constants, colossal magneto resistance and many more. These materials are different from conventional semiconductors like Si or simple metals like Al in which the charge of the electrons moving in amongst atoms plays the important role in determining the applications. Transition metal oxides often are electrical insulators and magnetic because of the strong repulsive interaction between the electrons. However chemical substitution can turn such magnetic insulators into high temperature superconductors (Nobel Prize 1988) and cause other dramatic changes in their properties. The basic physics governing their behaviour remains one of the biggest intellectual challenges of modern scientific research. Here the spin and orbital degrees of freedom and their interplay with the charge degrees of freedom of electrons play essential roles. With the recent development of the physical preparation of new oxide materials using an atom by atom deposition approach completely new materials and properties based on interfaces have been demonstrated opening up a new direction in material science and device applications. We will utilize the new experimental facilities we developed at UBC and the Canadian Light source for resonant X ray scattering and in situ atom by atom material preparation and apply these together with new theoretical insights to the study of surfaces, engineered interfaces and nanostructures of strategically selected transition metal oxides. This new facility is especially suited to study the electronic structure of buried interfaces which are hard or impossible to access in a non destructive manner with other methods. The spectacular properties found at such interfaces are predicted to potentially form a whole new platform for the next generation of electronic devices.

强相关电子系统表现出一些最有趣的物理特性，对于电子设备、可持续能源、生物医学设备、运输甚至量子计算中当前和未来的应用非常重要。由过渡金属和稀土化合物（例如其氧化物）制成的材料经常表现出极端特性，例如高温超导性、高热电势、高介电常数、巨大磁阻等等。这些材料不同于硅等传统半导体或铝等简单金属，在这些材料中，原子间移动的电子电荷在决定应用方面发挥着重要作用。由于电子之间强烈的排斥相互作用，过渡金属氧化物通常是电绝缘体和磁性的。然而，化学替代可以将此类磁绝缘体转变为高温超导体（1988 年诺贝尔奖），并导致其特性发生其他巨大变化。控制它们行为的基本物理学仍然是现代科学研究最大的智力挑战之一。在这里，自旋和轨道自由度及其与电子电荷自由度的相互作用起着至关重要的作用。随着最近使用原子沉积方法物理制备新型氧化物材料的发展，基于界面的全新材料和特性已被证明，开辟了材料科学和器件应用的新方向。我们将利用我们在 UBC 开发的新实验设施和加拿大光源进行共振 X 射线散射和原位逐个原子材料制备，并将这些与新的理论见解一起应用于战略选择的过渡金属氧化物的表面、工程界面和纳米结构的研究。这个新设施特别适合研究埋入界面的电子结构，而这些埋入界面很难或不可能用其他方法以非破坏性方式访问。预计此类接口的惊人特性将有可能为下一代电子设备形成一个全新的平台。