NSF-BSF: Elucidating Interactions between Multiple Optical Cycling Centers in Hypermetallic Polyatomic Molecules

激光冷却分子是探索量子科学和超冷物理前沿的有力工具，前提是它们的能量可以在所有自由度下冷却到非常接近绝对零度的温度。虽然某些类型的分子可以用精确设计的激光冷却，特别是那些含有单个重原子的分子，但将有效的激光冷却扩展到更普遍的分子是具有挑战性的。该项目旨在了解影响含有多个重原子的奇异、新型激光可冷却分子性能的一般设计原则。通过美国国家科学基金会-美国以色列两国国家科学基金会的合作实验项目，研究人员将探索从射电到可见光波长的光如何与这些分子相互作用。这一努力将扩大冷分子应用的多样性，从量子计算和模拟到桌面搜索新物理学。这种前沿但又基础的测量方法非常适合教育和培训STEM领域的学生，这种指导是项目的核心目标。迄今为止，所有直接激光冷却的演示都使用了含有单个重原子光子循环中心的分子。包含多个光中心的更复杂的物质有可能大大增加激光冷却分子的多功能性，但尚未在实验中得到充分的探索。该计划包括对含有多个碱土或类碱土原子的取代碳氢化合物（包括乙炔链和苯环）进行系统的光谱研究。通过结合宽带光学和微波数据，研究人员将直接探索电子结构和化学键的复杂性如何影响与激光冷却应用相关的分子性质，以及这些外来的、双基物质的分子物理学。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。

Laser-cooled molecules are a powerful tool for exploring the frontiers of quantum science and ultracold physics, provided their energy can be cooled in all degrees of freedom to temperatures very close to absolute zero. Although certain classes of molecules can be cooled with precisely engineered laser-light, particularly those containing a single heavy atom, extending efficient laser cooling to molecules more generally has proven challenging. This project aims to understand the general design principles that affect the performance of exotic, new classes of laser-coolable molecules containing multiple heavy atoms. Through a collaborative National Science Foundation - US Israel Binational Science Foundation experimental program, the investigators will explore how light from radio to visible wavelengths interacts with such molecules. This effort will broaden the diversity of cold molecule applications spanning quantum computing and simulation to tabletop searches for new physics. Such cutting-edge yet fundamental measurements are well suited to educating and training students in STEM fields, and such mentorship is a core project aim.All demonstrations of direct laser-cooling to date have used molecules containing a single heavy-atom photon-cycling center. More complex species containing multiple optical centers have the potential to greatly increase the versatility of laser-cooled molecules, but have not been thoroughly explored experimentally. This program comprises a systematic spectroscopic study of substituted hydrocarbons, including acetylene chains and benzene rings, containing multiple alkaline earth or alkaline-earth-like atoms. By combining broadband optical and microwave data, the investigators will directly probe how the intricacies of electronic structure and chemical bonding influence the molecular properties relevant to laser-cooling applications, as well as the molecular physics of these exotic, biradical species in general.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.