text: Once an attosecond light source is available, one has to drive the pulse towards the sample of interest and, then, measure its dynamics.
  The most suitable experimental observables to analyze the electron dynamics in matter are:
  * Angular asymmetry in the velocity distribution of molecular photo-fragment.
  * Quantum yield of molecular photo-fragments.
  * XUV-SXR spectrum transient absorption.
  * XUV-SXR spectrum transient reflectivity.
  * Photo-electron kinetic energy distribution.
  The general strategy is to use a pump-probe scheme to "image" through one of the aforementioned observables the ultra-fast dynamics occurring in the material under investigation.