Application of XUV and Soft-x-ray Attosecond Spectroscopies to Quantify Vibronic Couplings and Charge Dynamics

应用 XUV 和软 X 射线阿秒光谱量化电子振动耦合和电荷动力学

基本信息

批准号：
2207641
负责人：
Arvinder Sandhu
金额：
$ 39.86万
依托单位：
University of Arizona
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-07-15 至 2025-06-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2207641&HistoricalAwards=false
关键词：
Application XUV Soft ray Attosecond

项目摘要

The primary quantum process behind many phenomena in our daily lives is the light-driven motion of electrons. Important examples of this include photosynthesis, vision, vitamin D synthesis from sunlight, DNA damage by UV light, and more. As a first step towards developing a better understanding of such phenomena, it is important investigate and harness the electronic motions inside atoms and simple molecules with light pulses. However, the electrons are extremely fast, and can move on the timescale of an attosecond – a billionth of a billionth of a second! To capture the images of what transpires in the quantum realm at such dizzying speeds, one needs to use a sophisticated camera alongside an extremely fast flash or strobe light. The PI’s team employs advanced technologies such as a charged particle velocity imaging detector, which serves the purpose of a camera film, and ultrafast laser pulses that play the role of a strobe light. The proposed research project will investigate how electronic charge gets distributed after excitation by light, and how the changes in atomic positions within a molecule impact this process. Graduate and undergraduate students working on this this project will develop an important scientific skillset and will be empowered to generate new ideas and devise applications of their research. This impact will multiply as they move to the next stage of their careers in universities, national labs, and tech companies, thus fostering scientific innovation and productivity in the society.Attosecond extreme ultraviolet and soft-x-ray spectroscopy techniques form a very powerful toolkit for fundamental, real-time investigations of electron dynamics. In the proposed work, the PI and graduate students will employ these approaches for time-resolved study of coherent electronic wavepacket motion. Specifically, they will investigate XUV induced Rydberg, ionic, and many-electron excitations in atoms and molecules. To quantify the vibronic couplings that mix electronic states due to nuclear motion, the research team will conduct pump-probe measurements near conical intersections in small molecules. They will also aim to perform elementally specific transient absorption studies to monitor the coherent evolution of charge in photoionized molecules. Results obtained here will guide the development of theoretical methods that can accurately model the light-matter interaction, and the coupled and correlated evolution of electron and nuclei. The spatio-temporal mapping of charge dynamics in complex systems will serve to establish attosecond science as a versatile spectroscopy technique. These objectives will be achieved while training the graduate and undergraduate students in the frontier fields of attosecond science, laser technologies, and optical and x-ray spectroscopies. The PI will also place an emphasis on the participation of students from minority and underrepresented groups. Annual outreach events will be used to engage and educate the community about the importance and impact of physics research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

我们日常生活中许多现象背后的主要量子过程是电子的轻度运动。其中的重要例子包括光合作用，视觉，阳光的维生素D合成，紫外线损伤等等。作为对这种现象的更好理解的第一步，重要的是研究和利用原子内部的电子运动和带有光脉冲的简单分子。但是，电子非常快，可以在attosecond的时间范围内移动 - 十亿分之一的十亿美元！为了捕获以这种令人眼花speass乱的速度转换量子领域中的变化的图像，人们需要在非常快速的闪光灯或冲程灯的旁边使用复杂的摄像头。 PI的团队员工高级技术，例如带电的粒子速度成像探测器，该检测器可实现相机膜的目的，并且超快激光脉冲起作用，这些激光脉冲起到了中风灯的作用。拟议的研究项目将研究电子电荷在光线激发后如何分布，以及分子内原子位置的变化如何影响该过程。从事该项目的研究生和本科生将发展一个重要的科学技能，并有权产生新的想法并设计其研究的应用。随着他们在大学，国家实验室和科技公司的职业生涯的下一个阶段，这种影响将繁殖，从而促进了社会的科学创新和生产力。2秒极端紫外线和软X射线光谱技术构成了非常有力的工具包，用于基本的，实时的电子动力学。在拟议的工作中，PI和研究生将采用这些方法进行相干电子波袋运动的时间分辨研究。具体而言，他们将研究XUV诱导的原子和分子中的Rydberg，Ionic和多电子兴奋。为了量化由于核运动而混合电子状态的振动耦合，研究团队将在小分子的临床交叉点附近进行泵探针测量。他们还将旨在进行基本特定的瞬时滥用研究，以监测光电离分子中电荷的连贯演变。此处获得的结果将指导理论方法的开发，该方法可以准确地模拟光 - 物质相互作用，以及电子和核的耦合和相关的演变。复杂系统中电荷动力学的时空映射将有助于建立AttoSend Science作为多功能光谱技术。这些目标将在培训Attosecond科学，激光技术以及光学和X射线光谱的前沿领域的研究生和本科生时实现。 PI还将强调来自少数群体和代表性不足的学生的参与。年度外展活动将用于吸引和教育社区有关物理学研究的重要性和影响。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，被视为通过评估来获得珍贵的支持。