Intense ultrashort light pulses comprising merely a few wave cycles became routinely
available by the turn of the millennium. The technologies underlying their production and …

In this review, we will focus on the theoretical aspects in observing and controlling the
electronic dynamics in few-electron atoms and molecules by attosecond pulses in different …

Photoionization is one of the fundamental light-matter interaction processes in which the
absorption of a photon launches the escape of an electron. The time scale of this process …

The wave nature of particles is rarely observed, in part because of their very short de Broglie
wavelengths in most situations. However, even with wavelengths close to the size of their …

The direct observation of molecular dynamics initiated by x-rays has been hindered to date
by the lack of bright femtosecond sources of short-wavelength light. We used soft x-ray …

The double photoionization of a molecule by one photon ejects two electrons and typically
creates an unstable dication. Observing the subsequent fragmentation products in …

When an atom is electronically excited, it relaxes by emitting a photon or an electron. These
carry essential information on the electronic structure of their emitter. However, if an atom is …

Few-photon multiple ionization of Ne and Ar atoms by strong vacuum ultraviolet laser pulses
from the free-electron laser at Hamburg was investigated differentially with the Heidelberg …

We publish three Roadmaps on photonic, electronic and atomic collision physics in order to
celebrate the 60th anniversary of the ICPEAC conference. In Roadmap I, we focus on the …

Despite decades of progress in quantum mechanics, electron correlation effects are still only
partially understood. Experiments in which both electrons are ejected from an oriented …