DCP Frontiers in Chemical Physics Talks – “Two Becomes Four: Towards Spin Surface Crossings For Charge Transfer Dynamics That Obey Momentum Conservation” and “Exploring the Roles of Nuclear Spins, Quantum Coherence, and Entanglement in Ultracold Chemistry”
10
October
2025
Dear Colleagues, We are excited to announce the next event in the online DCP Frontiers in Chemical Physics Seminar Series, taking place on Friday, October 10 from 12-1pm EST. We began the series with two excellent inaugural talks by Camille Bilodeau (University of Virginia) and George Schatz (Northwestern University). For those who could not attend, the recording with both talks is available here: https://engage.aps.org/dcp/resources/webinars/past-webinars Upcoming October 10 Talks • Dr. Tian Qiu (Princeton University) “Two Becomes Four: Towards Spin Surface Crossings For Charge Transfer Dynamics That Obey Momentum Conservation” Abstract: Charge transfer dynamics typically involve surface crossings between two diabatic states, where spin states are often treated as degenerate. We have developed a phase space approach that, by enforcing total momentum conservation, naturally breaks spin degeneracy in a manner that depends on nuclear motion, splitting the crossing of two surfaces into four surfaces. Equipped with a constrained complete active space (CAS) method to efficiently generate charge transfer surfaces, our framework aims to reveal how nuclear motion couples to electron angular momentum and influences spin dynamics through spin-orbit coupling. This work seeks to provide a new perspective for understanding charge transfer processes and detailed spin dynamics, with potential implications for phenomena such as chirality-induced spin selectivity (CISS). • Prof. Kang-Kuen Ni (Harvard University) “Exploring the Roles of Nuclear Spins, Quantum Coherence, and Entanglement in Ultracold Chemistry” Abstract: Nuclear spins are usually not thought to participate in chemical reactions. However, in the ultracold temperature regime, we have a new opportunity to examine this general statement with quantum mechanical details. In this talk, I will present our ongoing investigations into the roles of nuclear spins, quantum coherence, and entanglement in molecule-molecule reactions, utilizing a one-of-a-kind ultracold KRb molecule apparatus [1]. There will be surprises and puzzles. If there is time, I will also report entangling individual trapped NaCs molecules in optical tweezers and realizing a quantum logic gate with trapped molecules [2]. [1] Quantum interference in atom-exchange reactions, Science 384, 1117 (2024) [2] Entanglement and iSWAP gate between molecular qubits, Nature 637, 821 (2025) Register here for the October 10 talks: https://apsphysics.zoom.us/meeting/register/KaO1WFjGS8GPcvwchPs_mw Future Talks in the Series • November 14: Bryan Changala (CU–Boulder) & Spiridoula Matsika (Temple University). Registration link: https://apsphysics.zoom.us/meeting/register/yy7UtsBGRpSjoyJ9Fr84ag • December 12: Dorothee Schaffner (University of Würzburg) & Naomi Ginsberg (UC–Berkeley). Registration link: https://apsphysics.zoom.us/meeting/register/TQKeDqrCTXO4lGgwBIp3EA Get Involved • Recommend a Speaker: Do you have suggestions for future speakers and moderators (e.g., Spring 2026)? Submit your recommendations here: https://forms.aps.org/t/kBaAqAkFxFus • Submit Your Abstracts: Don’t forget the deadline to submit abstracts for the APS March Meeting is October 23. Submit here: https://summit.aps.org/attend/abstracts/