ULYSSES · ManipULation of photoinduced processes bY reshaping tranSition StatEs via transient Strong coupling

Photochemistry deals with the light-assisted transformation of molecules into useful products. These processes are routinely manipulated by chemical modification and external laser driving. Femtosecond coherent control uses ultrashort pulses to initiate and actively modulate a chemical reaction. However successful control of efficiency and specificity of a chemical process is still awaited.ULYSSES proposes a radical departure from the way chemical processes are currently controlled by light. I will introduce an innovative “transient polaritonic control” for manipulation of photoinduced processes, using polaritons (hybrid light-matter states in strong coupling regime) activated on demand in optical nanocavities. I will exploit tunable resonances in metasurfaces (nanostructure arrays) excited by ultrashort pulses for controlling the energy landscape of molecules. Reconfigurable molecular/metasurface “metacavities” will switch on/off strong coupling for real-time selective reshaping of transition states, that I will apply to the proof-of-principle control of a photoisomerization reaction.The project proposes a paradigm-shift in coherent control through three objectives, combining physical chemistry with ultrafast nanophotonics, which perfectly suit my scientific profile.1) Develop a novel multidimensional “kD Spectroscopy” for characterizing fundamental processes in strongly coupled systems with the unprecedented combination of temporal and momentum resolutions.2) Design and characterize reconfigurable metasurfaces with ultrafast all-optical tuning of resonances to enable transient strong coupling.3) Demonstrate the manipulation of the energy landscape of a photoisomerization by reshaping the transition states via transient strong coupling in a metacavity.I foresee my unique approach will transform chemical control by enabling real-time manipulation of the desired reaction pathways with potential for quantum chemistry, remote control, site-selectivity, catalysis.