题目：超快极化激元动力学：化学动力学与量子信息科学的新应用

报告人：Prof. Wei Xiong

时间：2023年11月1日（星期三）16：00-17:00

地点：霞光楼200号

邀请人：严畅 副教授

报告人简介

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 B.S. degree from Peking University, China, in 2006. He then joined Prof. Martin Zanni's group at the University of Wisconsin, Madison, and completed his Ph.D. degree in 2011. Wei then moved to the University of Colorado, Boulder, in 2011, where he worked with Prof. Margaret Murnane and Henry Kapteyn. He joined thefaculty 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, guest molecule adsorptionsin self-assembled materials, femtosecond charge transfer dynamics on organic material interfaces. Wei is a recipient of Sloan Research Fellow, Coblentz Award, and Journal of Physical Chemistry C Lectureship.

近期关于超快极化激元的新进展：Science, 2020, 368, 665-667; Science, 2022, 378, 790-794; Acc. Chem. Res. 2023, 56, 776–786.

报告摘要

Through the strong coupling of molecular vibrational modes with photonic modes, intriguing molecular vibrational polariton states and dark reservoir modes emerge. These polaritons, exhibiting a dual nature of matter and light, have the potential to modify chemical reactions under thermally activated conditions, paving the way for the emerging field of polariton chemistry. Distinguishing polaritons from dark modes has been challenging, but ultrafast two-dimensional infrared (2D IR) spectroscopy proved instrumental in overcoming this hurdle. Our research demonstrated that polaritons facilitate intra- and intermolecular vibrational energy transfer, providing a means to control vibrational energy flow in liquid-phase molecular systems. Moreover, in studying a single-step isomerization event, we confirmed polaritons' role in modifying chemical dynamics under strong coupling conditions, while dark modes behaved like uncoupled molecules, leaving dynamics unchanged. This finding solidified the central concept of polariton chemistry and laid the groundwork for designing future polariton cavities. Beyond polariton chemistry, we leveraged 2D IR spectroscopy to explore molecular polaritons as a quantum simulation platform, revealing their potential for coherence transfer and non-Hermitian dynamics. Challenges remain, but understanding polaritons opens new possibilities in chemistry and quantum information science.