2.1 Time-resolved XUV-science

We combine XUV pulses as short as 100 attoseconds (1/10-th of a millionth of a billionth of a second!) with few-cycle visible or near-infrared (NIR) pulses. We use the pulses to explore – and eventually steer in real-time – the electronic motion in isolated systems. Helped by advanced theory tools, we aim to provide a detailed understanding of the collective and correlated electron dynamics in molecules and nano-particles exposed to strong laser fields.

We aim at better understanding of strongly-coupled electron and nuclear dynamics at conical intersection in neutral molecules. Conical intersections are ubiquitous in nature. They govern many elementary photophysical and photochemical processes, pertinent to a large number of research areas, from astrophysics, astrochemistry, and atmospheric chemistry, to biochemistry and biology to synthetic organic and inorganic chemistry. In this context, XUV and X-ray pulses are particularly useful due to the strong localization of inner-shell orbitals they probe. XUV and X-ray transitions are element-specific and chemically selective. The inner-shell binding energies show characteristic chemical shifts and provide a local probe of the bonding environment of the reporter atom. Time-resolved X-ray spectroscopy enables the “real-time” and real-space investigation of ultrafast photochemical reactions.

We investigate the femtosecond relaxation dynamics following interaction of molecules and nanoparticles with ultrashort XUV and X-ray pulses. Our goal is to understand photoionization and fragmentation mechanisms of isolated systems at these wavelengths.

We combine the ultrashort pulse duration with the high photon energy provided by FEL and HHG sources to investigate both collective and correlated electron dynamics in nanoparticles using coherent diffractive imaging (CDI) and time-resolved photoelectron and photoion spectroscopy. We aim to spatially resolve at the nanoscale ultrafast electron dynamics in relatively large nanoparticles.