Unusual Light-molecule Interactions: Polariton Condensates and Other Nonlinear Phenomena

Dr. Joel Yuen-Zhou, UC San Diego

Host: Dr. Pratyush Tiwary

Abstract: Confinement of molecules in optical microcavities gives rise to collective strong light-matter coupling and the formation of hybrid light-matter modes known as polaritons. While these modes potentially offer unusual chemical reactivity, their use is limited by their very short lifetimes owing to an entropic flow of population into the so-called dark modes. However, past a certain threshold of optical pumping, the population of polariton modes can become self-catalytic, giving rise to a nonequilibrium version of Bose-Einstein condensation. Polariton condensation has been routinely demonstrated with organic dyes at room temperature since the last decade. I will provide a chemical outlook for these condensates, demonstrating that their photochemical reactivity can be rather rich and different from plain laser-driven molecules.  
                In the second part of my talk, I will discuss interesting connections between topological phases of matter and chiroptical spectroscopy of molecules, describing a scheme to distinguish molecular enantiomers using the recently introduced ideas of topological frequency conversion.

Statistical Physics Seminar