Events

Vibrational Polariton Enabled Ultrafast Energy Transfer

Professor Wei Xiong, Professor and Kent Wilson Faculty Scholar, Department of Chemistry and Biochemistry, University of California, San Diego

Presented in person in Goergen 101 and on Zoom

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Abstract

Photonic modes can strongly couple to molecular vibrational modes, forming hybridized light-matter states, known as polaritons. Such a state adapts the properties of both light and matter, enabling new properties. In this talk, I will discuss how photonic environments can modify molecular dynamics through excited vibrational polariton states. Using two-dimensional infrared (2D IR) spectroscopy, we have demonstrated that strong coupling to photonic environments can efficiently promote energy transfer within or between molecules, subsequently slowing down competing reaction pathways. We further explored the criteria to fulfill polariton-enabled energy transfer, by which we discovered and verified a new principle to enable intermolecular energy transfer through polaritons in disorder materials. Lastly, we demonstrated that polariton can propagate its excitation in space, from which we determined the number of active polariton states versus the inactive dark states. This research progress provides insights on what excited vibrational polariton can do, laying design principles for new photonic structures to influence chemical processes.

Biography

Professor Wei Xiong is a Professor and Kent Wilson Faculty Scholar in the Department of Chemistry and Biochemistry at the University of California, San Diego. Wei received his BS degree from Peking University, China, in 2006. He then joined Professor Martin Zanni’s group at the University of Wisconsin, Madison, and completed his PhD degree in 2011. At Madison, Wei focused on developing novel 2D vibrational spectroscopy (transient 2D IR and heterodyne 2D SFG spectroscopy) to study molecules on solid-state material surfaces. Wei then moved to the University of Colorado, Boulder, in 2011, where he worked with Professor Margaret Murnane and Henry Kapteyn to develop the table-top XUV source for ultrafast measurements and time-resolved photoelectron spectroscopy for nanoparticles. He joined the faculty at the University of California San Diego in 2014. At UCSD, Wei’s research focuses on using and developing ultrafast nonlinear spectroscopic and imaging tools to reveal molecular structures and dynamics of materials, including ultrafast dynamics of polaritonic systems, biological self-assembly, femtosecond charge transfer dynamics on organic material interfaces. Wei is a fellow of the American Association of the Advancement of Science and American Physical Society, a recipient of Sloan Research Fellow, Coblentz Award, National Brown Investigator Award, and Journal of Physical Chemistry C Lectureship, TRVS Young Investigator Award, and a finalist of the Blavatnik National Awards for Young Scientists.