RUI: Atomic Physics with A Twist

在原子尺度上成像和控制电子动力学的能力使人们对原子结构和相互作用有了更深入的了解，这反过来又激发了显微镜、量子计算和量子通信等领域的技术进步。许多这些进步使用超短光脉冲或电子束来控制和观察原子电子在自然阿秒时间尺度（十亿分之一秒的十亿分之一）上的能量和动量特性。最近，所谓的扭曲阿秒激光脉冲和电子束已经可用。这些光束携带轨道角动量，这为不仅控制原子电子的能量和动量特性，而且控制它们的旋转特性打开了大门。本研究将建立并应用超短扭曲激光脉冲和扭曲电子束成像和控制原子电子旋转特性的理论模型。它将通过开发研究扭曲电子产生的新技术，表征以前无法进入的原子态的时间动力学，以及建立使用量子计算应用创建原子态的效率，促进阿秒物理学的进步。这些项目将为未来的实验和技术发展提供理论基础，展示扭曲光和电子在控制原子水平旋转运动方面的优势，并增强美国在阿秒物理学中的影响力。此外，该研究将通过为本科生提供前沿研究机会来培养下一代科技劳动力，这些本科生将通过亲身参与模型的开发、实施和分析，获得必要的职业技能。学生们将在地区和国家会议上展示他们的成果，使他们对科学研究有更多样化的看法，并增加他们从事科学和技术职业的机会。本研究将使用计算建模来(1)开发利用拉盖尔-高斯光涡旋脉冲的扭曲阿秒能量和角条纹的新技术；(2)确定扭曲光学和电子波包是否可以提高用于量子计算应用的圆形里德伯原子生产效率。在第一个项目中，我们将结合光学涡旋波包和阿秒条纹技术，研究角动量对扭曲光电子产生的影响，磁亚能级之间的电离时间延迟，以及不同角动量状态下的隧穿势垒。计算将使用时变薛定谔方程和半经典模型进行，以提供定量和定性的见解。这项研究将产生理论模型，勾勒出新的扭曲阿秒条纹技术，并将对基础量子力学和固体物理中的化学反应控制和电荷迁移等领域的应用产生深远的影响。在第二个项目中，将确定扭曲光子和电子用于创建圆形里德伯态的效率。这项研究将产生一个全面的数据集，详细说明通过扭曲波包激励最容易获得的里德伯态，并为未来有可能改变量子计算和量子模拟等领域的应用提供急需的信息。这两个项目都将通过为从大一到高年级的不同群体的本科生提供尖端的培训机会来增强伊利诺伊州的STEM劳动力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The ability to image and control electron dynamics at the atomic scale has led to a deeper understanding of atomic structures and interactions, which in turn has inspired technological advances in areas such as microscopy, quantum computing, and quantum communication. Many of these advances use ultrashort light pulses or electron beams to control and observe energy and momentum properties of atomic electrons on their natural attosecond timescale (a billionth of a billionth of a second). Recently, so-called twisted attosecond laser pulses and electron beams have become available. These beams carry orbital angular momentum, which opens the door to controlling not just the energy and momentum properties of atomic electrons, but also their rotational properties. This research will develop and apply theoretical models for using ultrashort twisted laser pulses and twisted electron beams to image and control the rotational properties of atomic electrons. It will promote the progress of attosecond physics by developing new techniques for studying twisted electron creation, characterizing the temporal dynamics of previously inaccessible atomic states, and establishing the efficiency of the creation of atomic states used quantum computing applications. These projects will provide the theoretical underpinning for future experiments and technological developments, demonstrate the advantages of twisted light and electrons in controlling atomic-level rotational motion, and enhance the U.S. influence in attosecond physics. In addition, the research will train the next generation of the science and technology workforce by providing cutting-edge research opportunities to undergraduate students who will gain necessary career skills through hands-on participation in model development, implementation, and analysis. Students will present their results at regional and national conferences, giving them a more diverse view of scientific research and enhancing their access to science and technology careers.This research will use computational modeling to (1) develop the new techniques of twisted attosecond energy and angular streaking using Laguerre-Gauss optical vortex pulses and (2) determine if twisted optical and electron wave packets can improve the efficiency of circular Rydberg atom production for use in quantum computing applications. In the first project, the research will combine optical vortex wave packets with attosecond streaking techniques to study the effects of angular momentum on the creation of twisted photoelectrons, the ionization time delay between magnetic sublevels, and the tunneling barriers of different angular momentum states. Calculations will be performed using the time-dependent Schroedinger equation and semi-classical models to provide both quantitative and qualitative insight. This research will result in theoretical models that outline new twisted attosecond streaking techniques and will have far-reaching implications for fundamental quantum mechanics and applications in fields such as chemical reaction control and charge migration in solid state physics. In the second project, the efficiency with which twisted photons and electrons can be used to create circular Rydberg states will be determined. The research will result in a comprehensive dataset detailing which Rydberg states are most accessible through twisted wave packet excitation and provide much-needed information for future applications that have the potential to transform fields such as quantum computing and quantum simulation. Both projects will enhance the Illinois STEM workforce by providing cutting-edge training opportunities to a diverse group of undergraduate students from the freshman to senior level.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.