Research project Timing many-body effects in small quantum systems
When atomic systems are exposed to light it is the electrons that react first. They absorb the radiation and convert the photon energy into excitation and ionization. Ultra-short light pulses are tools to study this dynamics in real time.
The goal of attosecond science is to understand, and ultimately control, electron dynamics on its natural time-scale. One
most interesting sequence of events follows the creation of a so-called core-hole in an inner shell of the atom. The sudden
removal of an electron initiates screening and relaxation processes through the subtle interplay between the remaining
electrons. With ultra-short light pulses the creation of the core hole can be clocked precisely and the onset of the events that
follow can be studied as a function of time. We work with theory and calculations to extract key information from
experiments and to deepen our understanding of electron dynamics.
Extremely short bursts of coherent light are today routinely generated in many laser laboratories around the world. The
shortness of these bursts, typically around hundred attoseconds (1 as = 10^(-18) s), has enabled time-domain studies of
electronic processes. Although the fantasy image of a camera fast enough to film the motion of the electrons is too
naive, it still describes the essence of attosecond science to some extent. We build theoretical and computational tools for
the interpretation and quantitative description of experimental observations with attosecond light sources. It is precisely
because the snap-shot camera idea is too simplified, that our focus is on how timing information can be obtained, and how
it should be interpreted.