Quantum Dynamics of Rydberg Atoms in Molecules and in Optical Lattices

自诞生以来，量子力学就引起了科学家和非科学家的兴趣，因为它预测了令人难以置信的现象，这些现象似乎击败了常识。这些包括隧道效应（粒子穿透墙壁），纠缠和非定域性（似乎与狭义相对论和因果关系不相容的远程幽灵行动），以及大型物体的量子相干性。该项目旨在利用量子力学规则实现分子物理学领域的目标，捕获结构中大粒子（里德伯原子）的量子动力学，以及测量基本常数的高精度光谱学。这些领域的工作促进了基础科学和应用科学的进步，对国家在技术基础设施和国防方面的持续进步至关重要，对保持国际竞争力也是必要的。通过学生的参与，该项目还有助于发展一支有能力的科学工作队伍，这对技术驱动的经济至关重要。研究重点是里德堡原子的量子动力学研究。这些原子具有处于高度激发态的电子，导致具有许多量子力学状态的丰富内部电子结构。增加了对原子质心运动的量子描述，以达到一个全面的量子力学描述，包括内部和外部自由度，需要在理论和实验研究中实现新的目标。高精度激光光谱学的方法被用来测量光学和亚太赫兹原子跃迁，允许人们确定原子和离子的极化率，以及里德伯常数。这项工作的高精度测量部分很重要，因为它有助于解决最近在先进基础科学中出现的被称为“质子半径之谜”的挑战。 在周期性激光产生的威尔斯（光学晶格）中捕获的里德堡原子的质心运动表现在振动分辨的晶格调制光谱中，表现在由作用在原子上的电偶极子力引起的布洛赫振荡中，以及表现在原子干涉效应（如塔尔博特效应）中。这些方面可使其自身适合于未来的实际测量和感测应用。在里德伯分子中，改进的原子局域化工具和亚原子长度尺度上里德伯原子的时间分辨成像使振动动力学的直接研究成为可能。这个组件是重要的，因为它推进了对涉及分子结合范式的新型分子的理解，直到最近，这是未知的。这项工作伴随着对里德堡原子的光学圆化的研究，作为光谱数据的全光学读出的多光子电磁感应透明的持续发展，以及使用光学腔追求超清洁的光学晶格势。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Since its inception, quantum mechanics has intrigued both scientists and non-scientists alike due to its prediction of mind-boggling phenomena that seem to defeat common sense. These include the tunnel effect (particles penetrating through walls), entanglement and non-locality (long-range spooky actions that seem incompatible with special relativity and causality), and quantum coherence of large objects. This project aims at harnessing quantum-mechanics rules to achieve objectives in the fields of molecular physics, the quantum dynamics of large particles (Rydberg atoms) in trapping structures, and high-precision spectroscopy to measure fundamental constants. Work in these areas furthers progress in fundamental and applied science, is important for continued national progress in technological infrastructure and defense, and is necessary to maintain competitiveness within the international landscape. Through student involvement, the project also contributes to the development of a capable scientific workforce, which is essential for a technology-driven economy.The research is focused on quantum-dynamical studies of Rydberg atoms. These are atoms that have an electron in a highly excited state, leading to a rich internal electronic structure with many quantum-mechanical states. A quantum description of the atomic center-of-mass motion is added to arrive at a comprehensive quantum-mechanical description that includes both internal and external degrees of freedom, needed to accomplish new goals in both theoretical and experimental research. Methods of high-precision laser spectroscopy are employed to measure optical and sub-Terahertz atomic transitions, allowing one to determine atomic and ionic polarizabilities, as well as the Rydberg constant. This high-precision-measurement component of the work is important because it helps solving a challenge known as the "proton radius puzzle", which has recently arisen in advanced fundamental science. The center-of-mass motion of Rydberg atoms trapped in periodic, laser-generated wells (optical lattices) is manifest in vibrationally resolved lattice modulation spectra, in Bloch oscillations induced by electric-dipole forces acting onto the atoms, and in atom-interferometric effects (such as the Talbot effect). These aspects may lend themselves to future practical measurement and sensing applications. In Rydberg molecules, improved atom localization tools and time-resolved imaging of the Rydberg atoms on sub-atomic length scales enable direct studies of vibrational dynamics. This component is important because it advances the understanding of novel classes of molecules that involve paradigms of molecular binding that were, until recently, unknown. The work is accompanied by studies on optical circularization of Rydberg atoms, the continued development of multi-photon electromagnetically-induced transparency as an all-optical readout of spectroscopic data, and the pursuit of ultra-clean optical-lattice potentials using optical cavities.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.