EAGER: Coherent Manipulation and Quantum Entanglement in Ultracold Reactions

Harvard University, Cambridge MA

Investigators

Abstract

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.