Vanderbilt Institute of Nanoscale Science and Engineering Colloquium
Dr. Kevin Kubarych
University of Ottawa
Polaritonic Chemistry and Dynamics
02.19.25 | 4:10PM | 5326 Stevenson Center
Exciting new prospects are emerging to modify rates and yields of chemical reactions by coupling vibrational states of molecules to resonant optical cavities. Polaritonic states are light-matter hybrids of an optical mode and many molecular vibrations which exhibit new dynamical behavior and can influence chemical reactivity. Though the mechanism of reaction modification is still unknown, we expect some role of both statistical thermodynamics and ultrafast dynamics will enter into a complete description. My presentation will introduce the background of polaritonic chemistry, highlighting recent successes and some of the challenges in carrying out chemical reactions inside microcavities. I will also describe the work we have done to apply ultrafast two-dimensional infrared (2D-IR) spectroscopy to understand the non-equilibrium dynamics of vibrational polaritons. Vibrational energy transport in ordinary molecules in solution is typically a diffusive process limited by both the weak intermolecular coupling and the short lifetime of excited vibrational states. Vibrational strong coupling yields polaritons that are highly delocalized over potentially billions of molecules and one optical mode, so there is the possibility of ultra-long range energy transport. Using a new approach to monitoring polariton transport based on nonlinear IR spectroscopy (i.e. transient grating), we find signatures of relatively long range transport by virtue of the photonic character of vibrational polaritons.
Bio: A native of Brooklyn, NY, Kevin Kubarych studied physical chemistry at Brown University (Sc.B., 1996) working the lab of Prof. Peter Weber, doing research on pulse shaping effects of fiber Bragg gratings. Having been bitten by the ultrafast bug, he headed to the University of Toronto to work with Prof. R. J. Dwayne Miller on multidimensional, fifth-order Raman spectroscopy of liquids (Ph.D. 2003). Committed to the new field of multidimensional optical spectroscopy, Kevin moved to France, working in the Laboratoire d’Optique et Biosciences, a CNRS lab located at Ecole Polytechnique in Palaiseau. Supported by a Human Frontier Science Fellowship, he joined Drs. Manuel Joffre and Jean-Louis Martin to build a two-dimensional infrared spectrometer to study biomolecules and develop new techniques, such as chirped-pulse up conversion to detect broadband IR pulses. In 2005, he established his independent research group at the University of Michigan’s Chemistry department in Ann Arbor. At UM, Kevin has developed 2D-IR spectroscopy as a general tool to unravel complex dynamical phenomena in a range of contexts, from biophysics to organometallic catalysis. Some of his group’s current interests include in operando 2D-IR spectroelectrochemistry as well as using ultrafast spectroscopy to understand how strong coupling to optical cavities can alter chemical reactions. In 2024, Kevin and his wife, fellow ultrafast spectroscopist Professor Jennifer Ogilvie, are moving their research groups to the University of Ottawa.
Host: Lauren Buchanan