CAREER: Gas-Phase Molecular Polaritons: A New Platform for Chemistry under Strong Light-Matter Coupling

普林斯顿大学化学系化学结构、动力学和机理a （CSDM-A）项目的支持下，Marissa Weichman正在研究在与光强相互作用下气相化学过程是如何进行的。当分子被封闭在一个光学腔内，也就是说，在一个由反射镜制成的装置中，它可以产生一个强大的受限光场，就会形成一种叫做极化子的新状态。这些系统表现出光的一些不寻常的波状特性，并且似乎表现出与普通分子不同的反应性和光化学。支配极性离子分子的化学原理目前还没有被很好地理解。Weichman实验室正在研究在强腔耦合作用下孤立的气相分子的低温化学，以阐明最简单的分子极化子的行为。这些发现有可能为化学、材料科学和量子信息科学中的极化技术的实际应用提供信息。Weichman教授还在改革普林斯顿大学的本科生量子化学课程，目标是扩大量子科学研究界和劳动力的参与。Weichman实验室将专注于原始气相测量，其中极化反应动力学可以用量子态特异性研究，而没有溶剂化的复杂性。虽然分子极化现在已经在液体和固态系统中得到了很好的建立，但对于气相分子来说，获得足够强的光-物质相互作用仍然是一个挑战。Weichman实验室在分子配分函数小且不均匀线宽窄的低温条件下获得了气相强耦合状态。低温缓冲气池允许制备冷的、致密的分子集合。该源与反馈稳定的fabry - p<s:1>光学腔和精密激光方案相结合，以设计气相分子中单个旋转振动跃迁的强耦合。Weichman实验室将利用该仪器来研究包括双分子反应、光解离和光异构化在内的基准化学过程在腔耦合下是如何发生的。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。

With support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) Program in the Division of Chemistry, Marissa Weichman of Princeton University is studying how gas-phase chemical processes proceed under strong interactions with light. When molecules are enclosed within an optical cavity, that is, in a device built from reflective mirrors that create a strong confined light field, new states called polaritons can form. These systems exhibit some of the unusual wave-like properties of light and also appear to demonstrate reactivity and photochemistry distinct from ordinary molecules. The principles governing the chemistry of polaritonic molecules are not currently well understood. The Weichman Lab is studying the low-temperature chemistry of isolated, gas-phase molecules under strong cavity coupling to elucidate how the simplest molecular polaritons behave. These discoveries have the potential to inform practical applications for polaritonic technologies in chemistry, materials science, and quantum information science. Professor Weichman is also reforming undergraduate quantum chemistry coursework at Princeton with the goal of broadening participation in the quantum science research community and workforce. The Weichman Lab will focus on pristine gas-phase measurements wherein polariton reaction dynamics can be studied with quantum-state-specificity and without the complications of solvation. While molecular polaritons are now well established in liquids and in solid-state systems, attaining sufficiently strong light-matter interactions for gas-phase molecules has remained a challenge. The Weichman Lab accesses the regime of gas-phase strong coupling at cryogenic temperatures where molecular partition functions are small and inhomogeneous linewidths are narrow. A cryogenic buffer gas cell allows for the preparation of cold, dense molecular ensembles. This source is combined with a feedback-stabilized Fabry-Pérot optical cavity and precision laser scheme to engineer strong coupling of individual rovibrational transitions in gas-phase molecules. The Weichman Lab will harness this apparatus to investigate how benchmark chemical processes, including bimolecular reactions, photodissociation, and photoisomerization, occur under cavity coupling.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.