CAREER: Directly Measuring Spin-vibronic Dynamics in Photochemistry with Ultrafast Coherent 2D Spectroscopy

With support from the Chemical Structure and Dynamics (CSD) program, Professor James D. Gaynor is investigating ultrafast spin-vibronic dynamics in photomagnetic complexes, molecular qubits, and materials for quantum information sciences. As qubits and quantum sensors, molecules present key advantages to the emerging field of quantum information science by combining atomic precision with reproducible and tunable components and properties. However, there are significant challenges associated with understanding, controlling, and predicting the preparation and stability of coherent quantum states due to a lack of spectroscopic methods that can directly characterize these observables unambiguously. Professor Gaynor and his students will develop and use new ultrafast coherent two-dimensional spectroscopies that utilize circularly polarized ultrafast pulses, operating on femtosecond and attosecond timescales, to systematically characterize ultrafast spin-vibronic dynamics in a series of cobalt-centered photomagnetic complexes. Their studies will enable a new paradigm of how to tune spin-vibronic interactions in molecules and materials for future applications in quantum information sciences. In order to prepare the next generation of a quantum-enabled workforce, this work will also lower the activation barrier to high-power ultrafast laser and optics training while avoiding laser safety hazards for students of all ages by using a mobile virtual laser laboratory module that operates through virtual reality technologies. This research uses new ultrafast coherent multidimensional spectroscopies leveraging new polarization combinations and the presence of magnetic fields to understand how vibronic couplings and spin-orbit couplings in molecules are affected in Co-centered complexes as the ligands exert increasing influence over the photoexcited electronic behavior. The techniques developed and used in the Gaynor group include two-dimensional electronic-vibrational spectroscopy and two-dimensional electronic-XUV spectroscopy, which directly target vibronic couplings and metal-centered electronic spin states, respectively. The ligand’s influence over the Co-centered electronic dynamics will be measured and compared across a ligand series spanning “passive” to “active” through photoexcited states known to have greater involvement with the ligand, such as metal-to-metal charge transfer, ligand-to-metal charge transfer, and photoisomerization-induced spin-charge excited states. Collectively, this work will provide a thorough exploration and understanding of spin-vibronic coupling and it’s role in materials for quantum 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. NSF Award ID: 2541660 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: James Gaynor | Institution: Northwestern University at Chicago, EVANSTON, IL | Award Amount: $670,000 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2541660 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2541660.html