Quantum Dynamics of Rydberg Atoms in Molecules and in Optical Lattices

自量子力学诞生以来，由于它对似乎超越常识的令人难以置信的现象的预测，科学家和非科学家都对它产生了兴趣。其中包括隧道效应（粒子穿墙），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距离怪异行为），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来实现分子物理、捕获结构中大粒子（里德伯原子）的量子动力学和高精度光谱测量基本常数等领域的目标。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，对保持在国际格局中的竞争力是必要的。通过学生的参与，该项目还有助于培养一支有能力的科学队伍，这对技术驱动型经济至关重要。研究的重点是里德伯原子的量子动力学研究。这些原子有一个处于高度激发态的电子，导致丰富的内部电子结构具有许多量子力学状态。添加了原子质心运动的量子描述，以达到包括内部和外部自由度的综合量子力学描述，这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次太赫兹原子跃迁，允许一个确定原子和离子极化，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高级基础科学中出现的一个名为“质子半径谜题”的挑战。被困在周期性激光产生的阱（光学晶格）中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，表现在由作用于原子的电偶极子力引起的布洛赫振荡中，表现在原子干涉效应中（如塔尔博特效应）。这些方面可能有助于未来的实际测量和传感应用。在Rydberg分子中，改进的原子定位工具和亚原子长度尺度上的Rydberg原子的时间分辨成像使振动动力学的直接研究成为可能。这个组成部分很重要，因为它促进了对涉及分子结合范式的新型分子的理解，这些分子结合范式直到最近才为人所知。这项工作伴随着对里德伯原子的光学圆化的研究，作为光谱数据的全光读出的多光子电磁诱导透明的持续发展，以及利用光学腔追求超清洁的光学晶格势。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。

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.