Real time tracing of valence-shell electronic coherences with attosecond transient absorption spectroscopy

► Detailing the technique of attosecond transient absorption spectroscopy. ► Tracing the charge state time-resolved ionization of atoms. ► Real-time observation and reconstruction of valence electron motion in Kr+ ions. ► Observation of coherences in correlated multi-hole systems: Kr2+ and xenon ions.