EAGER: Coherent Manipulation and Quantum Entanglement in Ultracold Reactions

在化学系化学结构、动力学和机理项目（CSDM-A）的支持下，哈佛大学的倪康权教授将使用先进的激光技术来探索化学反应产物状态之间的量子纠缠。量子纠缠是量子信息科学（QIS）核心的一个关键概念，两个粒子可以占据一个共享的量子态，即使它们相隔很远。虽然电子和核自旋之间的纠缠，例如，在无机配位配合物中，孤立离子和金属中心之间的纠缠已经被观察到，但化学反应中产物状态可以纠缠的想法还没有被探索过。倪教授和她的团队将首先与反应物产生纠缠的核自旋态，然后在整个反应过程中利用反应物核自旋的守恒性来确定反应产物是否或多久保持相干性。确认化学反应产生的几代缠结产物对，将扩大已知的缠结产生方式，并允许化学系统进入列表，增加其额外的好处，例如允许捕获和操纵的自由度。倪教授将与高中生、本科生和研究生一起进行这项研究，从而对美国的量子劳动力产生积极影响。在一个简单的化学反应（2KRb—K2 + Rb2）中，量子纠缠在产物状态之间的作用正在被探索，以确定在化学反应产物中是否和多长时间保持相相干性。要做到这一点，首先要在单个反应物中产生纠缠核自旋态。在整个反应过程中，将使用基于双光子拉曼的方法来测量反应物核自旋的守恒，以建立各种产物之间的相干性。将通过共振增强双光子电离和重合探测相结合来探测产物居群的相关性。这个简单化学反应的结果有可能作为理解更复杂化学反应中的量子纠缠的蓝图，从而有可能在化学反应动力学和量子信息科学之间建立定量联系。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, Professor Kang-Kuen Ni of Harvard University will use sophisticated laser techniques to explore quantum entanglement between product states of a chemical reaction. Quantum entanglement is a key concept at the heart of quantum information science (QIS) whereby two particles can occupy a shared quantum state, even when separated over long distances. While entanglement between electron and nuclear spins in, for example, isolated ions and the metal centers in inorganic coordination complexes have been observed, the idea that the product states in a chemical reaction could be entangled has not been explored. Professor Ni and her group will first generate entangled nuclear-spin states with the reactants then will leverage the conservation of the reactant nuclear spins throughout the reaction to establish whether or how long coherence is preserved in reaction products. Confirming generations of entanglement product pairs from chemical reaction would expand the known ways that entanglement can be created and allow chemical systems to enter the list with added benefits such as their degrees of freedom that allow for their trapping and manipulation. Professor Ni will work with high school, undergraduate, and graduate students in this research thus positively impacting the Nation's quantum-enabled workforce.The role of quantum entanglement between the product states in a simple chemical reaction (2KRb -- K2 + Rb2) is being explored to establish whether and how long phase coherence is preserved in the chemical reaction products. To do so, entangled nuclear-spin states within the individual reactants will first be generated. The conservation of the reactant nuclear spins throughout the reaction will be measured using two-photon Raman-based approaches to establish coherence between the various products. Product population correlation will be probed by a combination of resonant enhanced 2-photon ionization and coincident detection. Results from this simple chemical reaction have the potential to serve as a blueprint for understanding quantum entanglement in more complex chemical reactions and thus have the potential to forge a quantitative connection between chemical reaction dynamics and quantum information science.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.