Electronic structure of solids and interfaces with strong electron-electron/Boson interactions

固体的电子结构和具有强电子-电子/玻色子相互作用的界面

• 批准号: RGPIN-2018-04671
• 负责人: Sawatzky, George
• 金额: $ 5.97万
• 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: 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=763084
• 关键词: Electronic; structure; solids; interfaces; strong

Our research is focused on obtaining a detailed understanding of the relationship between the chemical composition, the atomic and the electronic structure of materials and their physical properties, including the electrical, magnetic, optical and thermal properties that are determined primarily by valence electrons of the atoms and their propagation in the solid. In transition metal and rare earth compounds, the partially filled valence shell electrons have strong interactions resulting in alignment of their spins and ordering the occupation of the orbitals. This leads to, for example, local magnetic moments and electrical quadrupole moments, which order in the solid to form interesting magnetic and orbital ordering patterns with new and exotic physical properties.The physics of atoms and ions in solids and the propagation of electrons between them, coupled with the motions of the atoms, lie at the heart of being able to predict which structures, compositions and micro structures could lead to new and interesting physical properties. We develop theoretical and experimental methods to study the electronic structure of these correlated electron systems in detail. With the new X-ray spectroscopy beam line recently developed at the Canadian Light Source, we study the electronic structure of solids on an atomic scale. This includes the electronic structure of deeply buried interfaces in heterostructures of transition metal oxides. These interfaces have fascinating new properties such as the superconducting interfaces formed between two judiciously selected parent electrical insulators.We propose new directions in interface engineering, utilizing our newly developed molecular beam epitaxy method for atom-by-atom growth of new materials and interfaces. We also propose the development of a new and world-leading electron energy loss spectroscopy facility with unmatched energy and momentum resolution. This will be complimented with non-resonant hard x-ray inelastic scattering with high energy and momentum resolution to determine the large momentum energy loss region. This is crucial to determine the Crystal Local Field Corrections, which determine the electron-electron and electron phonon interactions in these correlated electron systems modified by screening and electronic solvation effects.We also propose to develop the theoretical and computational methods needed to interpret the experimental result and to predict potentially new structures with interesting physical properties. We note that this information is of crucial importance in systems that have a very non-uniform electron density and polarizability, as is mostly the case in the materials of interest here. This will be done in the strongly collaborative atmosphere of the Stewart Blusson Quantum Matter Institute and in collaboration with the UBC-Max Planck-U Tokyo Centre for Quantum Materials.

我们的研究重点是详细了解材料的化学成分、原子和电子结构及其物理特性之间的关系，包括主要由原子的价电子决定的电、磁、光和热特性以及它们在固体中的传播。在过渡金属和稀土化合物中，部分填充的价层电子具有很强的相互作用，导致它们的自旋对齐并有序占据轨道。例如，这会产生局部磁矩和电四极矩，它们在固体中有序排列，形成具有新奇物理特性的有趣的磁和轨道有序模式。固体中原子和离子的物理学以及它们之间的电子传播与原子的运动相结合，是能够预测哪些结构、成分和微观结构可以产生新的、有趣的物理性质的核心。我们开发理论和实验方法来详细研究这些相关电子系统的电子结构。利用加拿大光源最近开发的新型 X 射线光谱光束线，我们在原子尺度上研究固体的电子结构。这包括过渡金属氧化物异质结构中深埋界面的电子结构。这些界面具有令人着迷的新特性，例如在两个精心选择的母体电绝缘体之间形成的超导界面。我们提出了界面工程的新方向，利用我们新开发的分子束外延方法来逐原子生长新材料和界面。我们还建议开发一种新型的、世界领先的电子能量损失光谱设施，具有无与伦比的能量和动量分辨率。这将与具有高能量和动量分辨率的非共振硬 X 射线非弹性散射相辅相成，以确定大动量能量损失区域。这对于确定晶体局域场校正至关重要，晶体局域场校正确定了这些通过屏蔽和电子溶剂化效应修改的相关电子系统中的电子-电子和电子声子相互作用。我们还建议开发解释实验结果所需的理论和计算方法并预测具有有趣物理特性的潜在新结构。我们注意到，这些信息对于具有非常不均匀的电子密度和极化率的系统至关重要，就像本文感兴趣的材料中的大多数情况一样。这将在斯图尔特·布鲁森量子物质研究所的强有力的合作氛围中，并与 UBC-马克斯·普朗克大学东京量子材料中心合作完成。