Two spectroscopic approaches developed in the ATTO group provide access to attosecond dynamics:
- Photoemission spectroscopy
- Harmonic spectroscopy
Photoemission spectroscopy
The photoemission spectroscopy can be used to study a wide variety of electronic and nuclear dynamics in excited/ionized species, through their electronic valence- and inner-electronic layer.
Une application marquante est l’étude en temps réel du processus quantique de photoémission, que ce soit en phase gaz, liquide ou solide. Cette spectroscopie permet de mesurer les infimes délais entre l’émission d’électrons issus de différentes couches de valence et de coeur, et de quantifier les temps de piégeage des électrons sur des résonances intermédiaires.
A key application is the real-time study of the photoemission quantum process, whether in the gas, liquid or solid phase. This spectroscopy allows measuring the minute delays between the emission of electrons from different valence and core layers, and to quantify electron trapping times on intermediate resonances.
Combined with electron momentum imaging, we can reconstruct the 3D film of the wave packet ejection and access electronic correlations and rearrangements in the ion.
Harmonic spectroscopy
Harmonic spectroscopy, based on the process of generating high-order harmonics, is a highly efficient probe of the structure and dynamics of a target gas, combining attosecond time resolution with sub-Angström spatial resolution.
It enables the imaging of molecular orbitals by quantum tomography, and the study of attosecond electronic dynamics initiated by tunnel ionization, such as charge migration.
The accessible dynamics are those initiated in the inner or valence layer, and the possible measured delay range extends up to the period of the fundamental laser.
