R. B. King Lecture: Enabling Molecular Quantum Information Science with Electron Spins

Quantum technologies based on molecular electron spin coherence afford unique potential in miniaturization, spatial localization, and tunability through synthetic chemistry and biomolecular integration. However, many applications within molecular quantum information science hinge on slowing down spin relaxation, a process that effectively leaks quantum information into the environment. Additionally, applications such as quantum sensing with molecular quantum bits (qubits) have only recently undergone exploration. This talk will summarize the development and application of ligand field spin dynamics, a molecular paradigm to construct spin relaxation structure-function relationships from physical inorganic spectroscopic observables. This approach elucidates the critical bonding, symmetry, and ligand field vibronic excited-state coupling factors enabling room-temperature coherence, as measured by pulse electron paramagnetic resonance (EPR). The talk will further describe the development of a new spectroscopic technique to achieve ultrafast, all-optical measurements of molecular electron spin coherence in an unprecedented manner, which opens the door to new synthetic design and applications of molecular qubits.

Ryan G. Hadt received his B.S. and M.S. degrees in chemistry at the University of Minnesota Duluth (with V. N. Nemykin) and his Ph.D. at Stanford University (with E. I. Solomon). He was a visiting postdoctoral fellow at Harvard University (with D. G. Nocera) before continuing research at Argonne National Laboratory as a postdoctoral appointee (with L. X. Chen) and later as an Enrico Fermi Fellow. In 2018, he joined the faculty in the Division of Chemistry and Chemical Engineering at the California Institute of Technology. Professor Hadt’s research interests are broadly based in the fundamental understanding of transition metal electronic structure, with applications in catalysis, photophysics, and quantum information science.