Theory of complex oxides: superconductivity and interfaces

复合氧化物理论：超导性和界面

• 批准号: RGPIN-2018-04878
• 负责人: Atkinson, William
• 金额: $ 2.99万
• 依托单位: Trent University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762922
• 关键词: Theory; complex; oxides; superconductivity; interfaces

Modern technology---computers, cell phones, medical equipment---is possible because of a decades-long push towards making smaller and faster electronic devices. This exponential growth of computing power over time is known as Moore's law. As we begin to bump up against fundamental limits to Moore's law, interest is growing in broadening the capabilities of nano-electronic devices. For example, the past decade has seen significant amounts of basic research devoted to ferroelectric and magnetic materials that might, one day, be incorporated into new high-speed memory devices. To this end, research is moving away from traditional semiconductors into new families of materials. My work focuses on transition metal oxides.Transition metal oxides hold a lot of potential because they can have many properties---superconductivity, magnetism, ferroelectricity, and others---that are not found in conventional semiconductors. At present, the questions that need to be answered are very basic: can we understand, in terms of the fundamental laws of nature, how these materials behave? It turns out that many transition metal oxides have different physical properties in confined geometries (for example, nanodevices) than they do in large samples. Can we understand why? In my research, I construct computer models, based on fundamental laws of physics, to simulate the electronic properties of various transition metal oxides. With these models, I hope to explain the physical properties of simple oxide structures (interfaces and heterostructures), and to understand the subtle role played by impurities and defects.My research focuses on two families of materials: high temperature superconductors and strontium titanate interfaces. The first of these families was discovered almost 30 years ago, but continues to surprise us with new revelations of complex self-organised behaviour that emerges on nanometre scales. The second family has more immediate potential for applications in nanoelectronics, but also raises questions about how electrons behave at the nanometre scale; here the fundamental goal is to explore the vast range of possible properties that can be engineered into devices by appropriate choice of building materials and geometry.

现代技术——计算机、手机、医疗设备——之所以成为可能，是因为几十年来人们一直致力于制造更小、更快的电子设备。这种计算能力随时间呈指数增长的现象被称为摩尔定律。当我们开始遇到摩尔定律的基本限制时，人们对扩大纳米电子设备的功能的兴趣与日俱增。例如，在过去的十年里，大量的基础研究致力于铁电和磁性材料，有一天，这些材料可能会被纳入新的高速存储设备中。为此，研究正在从传统半导体转向新材料系列。我的工作重点是过渡金属氧化物。过渡金属氧化物具有很大的潜力，因为它们具有许多传统半导体所没有的特性——超导性、磁性、铁电性等。目前，需要回答的问题非常基本：我们能否根据自然的基本规律来理解这些材料的行为？事实证明，许多过渡金属氧化物在受限几何形状（例如纳米器件）中具有与在大样品中不同的物理性质。我们能明白为什么吗？在我的研究中，我根据物理基本定律构建计算机模型来模拟各种过渡金属氧化物的电子特性。我希望通过这些模型来解释简单氧化物结构（界面和异质结构）的物理性质，并了解杂质和缺陷所发挥的微妙作用。我的研究重点是两类材料：高温超导体和钛酸锶界面。 第一个家族大约在 30 年前被发现，但纳米尺度上出现的复杂自组织行为的新揭示仍然让我们感到惊讶。 第二个家族在纳米电子学领域具有更直接的应用潜力，但也提出了电子在纳米尺度上如何表现的问题；这里的根本目标是探索通过适当选择建筑材料和几何形状可以将其设计成设备的各种可能的特性。