Speaker: Thomas Pfeifer, MPIK Heidelberg
Program Description
Electrons bound in atoms and small molecules represent some of the most fundamental quantum systems. These systems are so well known and reliable that they serve as optical clockwork of the most precise clocks and even allow to test potential variations of physical constants. On the other hand, any exposure of such seemingly simple few-body quantum systems to strong electromagnetic fields completely changes their intrinsic properties and sets off dynamical processes that quickly challenge our understanding. Yet, the physical mechanisms behind these processes hold the key for engineering novel chemical reactions by light, and for using a single flash of intense x-rays to image a single molecule with free-electron lasers (FELs).
In this talk, we discuss recent experiments and understanding gained on some fundamental dynamical motifs of atoms and molecules exposed to strong laser fields. As ionization commonly occurs in both high-frequency as well as strong laser fields, here we specifically ask the questions as to what happens to an atom >before< it ionizes, and what happens to a small molecule >after< multiple ionization took place in an intense extreme-ultraviolet FEL pulse.
Interestingly, the insights gained from such experiments in simple systems can, on the one hand, be mapped to applications in more complex targets, and, on the other hand allow new avenues for precision metrology in thus far uncharted (x-ray) areas.
