FIP Seminar: Mimics of Chemical Barrier Crossing to Strange "Non-Reciprocal" Dynamics in Optical Matter
Wednesday, November 15, 2017
12:00 pm - 1:00 pm
Fitzpatrick Center Schiciano Auditorium Side B
Dr. Norbert Scherer, Professor, Department of Chemistry, University of Chicago
The interaction of light with matter is one of the primary means employed to understand the world around us, particularly from atomic and molecular scales and up. However, electromagnetic radiation can also be used to generate forces and momentum on systems for active manipulation. While these forces are relatively weak on macro-scales, they have realized great impact on the (sub-)microscale in biophysics, cell biology and nanoscience. This talk will present another direction - the creation of optical matter from nanoparticle building blocks by optical binding forces - to study barrier crossing phenomena in chemistry and the manifestation of non-reciprocal (non-conservative) dynamics. The new insights into barrier crossing and the applicability of widely-used theoretical descriptions based on Kramers theory are made possible by direct visualization of single particle dynamics vs. the unseeable dynamics that occur at the molecular level in Chemistry and Biophysics. Understanding (apparent) non-conservative dynamics of multi-particle optical matter systems, as manifest in "negative torque" and linear motion that seem to defy the actio et reactio principle of classical Physics requires considering optical matter as a many body system/problem with all-to-all relatively long range electrodynamic interactions.
Norbert Scherer received his BS in Chemistry from the University of Chicago in 1982 and a PhD in Chemical Physics from Caltech in 1989. His graduate work with Ahmed Zewail established the field of "Femtochemistry". As a NSF Postdoctoral Fellow with Graham Fleming at the University of Chicago he pioneered optical coherence spectroscopy methods with the realization of the importance of optical phase in nonlinear spectroscopy. He was an Assistant Professor at the University of Pennsylvania (1992-97) and has been a Full Professor at the University of Chicago since 1997. His research has evolved from a focus on nonlinear ultrafast optical spectroscopy of photophysical and photosynthetic systems to integration of scanning probe methods with ultrafast spectroscopy to single molecule science to nano-plasmonics and single molecule biophysics to now transport and function in cellular systems and dynamics of optical matter. He has received various distinctions including NSF National Young Investigator and Lucille and David Packard Fellowships, is a Fellow of the American Physical Society and Optical Society of America, received the 2015 Peter Debye Prize from the Edmond Hustinx Foundation, Maastricht, Netherlands and is currently a Department of Defense Vannevar Bush Faculty Fellow. He is/has been a research mentor to ~40 postdoctorals, 35 graduate students and ~40 undergraduate and high school students.