Direct Electron Detection Camera for Next-Generation Sensitivity in Ultrafast Electron Scattering Measurements

直接电子探测相机可提高超快电子散射测量中的下一代灵敏度

• 批准号: RTI-2023-00449
• 负责人: Siwick, Bradley
• 金额: $ 10.78万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 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=762586
• 关键词: Direct; Electron; Detection; Camera; Next

There is currently an enormous, worldwide effort directed at the development and application of new experimental methods that make it possible to directly `watch' the time evolving structure of matter. These approaches combine state-of-the-art femtosecond lasers (see Nobel Prize in Physics, 2018) and sources of either ultrashort xray or electron pulses to acquire time-resolved diffraction/scattering patterns and images. If time-resolution approaches ~10 femtoseconds, the timescale of the highest frequency vibrations in molecules and materials, atomic motion is essentially frozen during an observation and one can completely follow the fundamental dynamics to produce a "molecular movie"; the experimental equivalent of a molecular dynamics simulation. It is possible to watch chemical bonds break/form and directly determine transition-state structures for even complex reactions, to follow phase transition dynamics uncovering the deep connections between the structure and properties of materials, and directly observe the coupling between charge, orbital and lattice degrees of freedom in both momentum and time. This proposal is focused specifically on the further development of the World's most powerful ultrafast electron scattering instrument, designed, built and operating at McGill University. We are requesting a state-of-the-art direct electron detection camera to replace our existing obsolete detector, enhancing our detection sensitivity by at least an order of magnitude.  This new capability will open up a significant new 'scientific space' of phenomena that are undetectable with our current camera, shedding new light on materials phenomena as diverse as superconductivity, charge density waves, thermoelectricity, photovoltaicity and carrier mobility in semiconductors and metals. We will be in a position to investigate the complex interplay between strong, multiorbital electronic correlations, structural distortions, charge and orbital order across a range of strongly correlated material where this physics determines properties (transition metal oxides, pyrochlore oxides, manganites and cuprates), including the formation dynamics of quasiparticles in these systems that involve phonons.  In monolayer and bilayer materials we will be able to direct watch exciton-phonon and exciton-polaron coupling, and chiral phonon generation.  Further, there is also the possibility of discovering new photoinduced phases and avenues for optical control of complex materials, a topic at the forefront of materials research.

目前，有一种巨大的，全球的努力，致力于开发和应用新的实验方法，使得可以直接“观察”物质的时间结构。这些方法结合了最先进的飞秒激光器（请参阅诺贝尔物理学奖，2018年）和超短X射线或电子脉冲的来源，以获取时间分辨的衍射/散射模式和图像。如果时间分辨率接近约10个飞秒，则分子和材料中最高频率振动的时间表基本上在观察过程中冻结了原子运动，并且可以完全遵循基本动力学来产生“分子电影”。分子动力学模拟的实验等效物。可以观察化学键断裂/形成，并直接确定复杂反应的过渡状态结构，遵循相变动力学，发现材料的结构和性质之间的深度连接，并直接观察电荷，轨道，轨道，轨道和晶格之间的自由度之间的耦合。该提案专门集中于在麦吉尔大学设计，建造和运营的世界上最强大的超快电子散射工具的进一步发展。我们要求使用最先进的直接电子检测摄像头来替换我们现有的过时检测器，从而提高我们的检测灵敏度至少一个数量级。这种新的能力将为我们当前的摄像机无法检测到一个重要的现象的新型“科学空间”，从而在半导体和金属中为材料现象提供了新的材料现象，如材料现象，如超导性，电荷密度波，热电动性，光伏性，光伏性和携带者的迁移率。我们将能够研究强，多纤维电子相关性，结构扭曲，电荷和轨道顺序之间的复杂相互作用，这些材料范围很强的相关材料，在这些材料中，该物理学决定了特性（过渡金属氧化物，氧化甲状腺氧化物，锰矿，锰酸盐和粉结液），包括这些系统中涉及的Quasiparticles的形成动力学。在单层和双层材料中，我们将能够指导观看激动人心的Phonon和Interad-Polaron耦合以及手性声子的一代。此外，还有可能发现新的光诱导阶段和途径，以控制复杂材料，这是材料研究的最前沿的主题。