Research project Timing many-body effects in small quantum systems
Artistic illustration of how a train of attosecond pulses (blue) and a IR-laser pulse (red) interact with electrons in the two outer shells of Neon.
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.
