Time Resolved Spectroscopies

Following light-driven ultrafast excitation dynamics in a material can yield invaluable insights on the out-of-equilibrium material’s behaviour which can transferred to the design of controllable light-responsive devices. The technological development of pump-probe spectroscopies has allowed scientist to achieve attosecond time-resolution in charge dynamics of both molecular and extended systems but the interpretation of the experimental data strongly relies on theoretical modelling. The theoretical description of these highly out-of-equilibrium systems poses both conceptual and technical challenges, in particular when an atomistic interpretation is needed. To address these challenge we use and develop theoretical techniques based on a combination of Time-Dependent Density-Functional theory and Non-Equilibrium Green’s function theory, heavily relying on high performance scientific computers. We are particularly interested in light-induced phase transitions [1], light-dressing of electronic states [2] and stabilising charge-migration mechanisms in bio-relevant molecular systems [3].