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2.2 Strong-field Few-body Physics
Project coordinator(s): H. Rottke, F. Morales
"Time resolved single- and multi-electron strong field phenomena"


Present key activities

Theory of strong field dynamics

Strong-field dynamics typically begins with ionization. One of the questions we address theoretically is the attosecond dynamics of the ionization process. How long does it take an electron to tunnel out of the potential well through the barrier created by the interaction with the laser field? What is the effect in the angle-resolved electron spectrum of electrons tunneling out at different times and how does it depend on the binding potential? What is the role of electron-electron correlation during tunneling? How does the electron-electron correlation affect the shape of the hole created in a molecule? What happens to excited states of atoms and molecules at the laser intensities approaching and exceeding 1013 W/cm2, when the electric field of the laser pulse completely suppresses the binding potential and these states find themselves far above the barrier?

Multi-electron dynamics in molecules induced by strong field ionization
Sascha Birkner, Federico Furch, Arnaud Rouzée, Claus Peter Schulz

Strong field induced processes can give a detailed insight into molecular electron and nuclear dynamics. We will investigate here small and mid-size molecules with few cycle laser pulses at intensities of 1014 W/cm2 to understand excitation and ionization pathways, the induced multi-electron dynamics and the formation of electronic wave-packets.

Excitation and acceleration of atomic species in strong laser fields
Sven Meise, Henri Zimmermann, Ulli Eichmann

Atoms exposed to strong laser fields do not necessarily ionize. A substantial fraction of atoms is left in an excited state. In particular we investigate the processes leading to a) excited neutral atoms, b) neutral excited fragments after strong field dissociation of molecules, c) high survival rates of Rydberg atoms in strong fields. Moreover, the survival of atoms in neutral excited states goes along with ultra strong kinematic effects on neutral atoms in the focussed laser beam, which are investigated using a direct imaging technique of excited atoms.