In recent years, in part due to progress made in generating and controlling intense laser fields, the timescale of dynamical processes in atomic and molecular systems has been pushed into the attosecond regime. In parallel with experimental work, theoretical methods are being developed to treat explicitly time-dependent electronic motion after photoexcitation on ultrashort timescales. In the presentation, I will review wave-function based, correlated many-electron methods and their application to femtosecond-laser driven dynamics. Specifically, we will be concerned with multi-determinant expansions of the N-electron wavefunction such as time-dependent configuration interaction (TD-CI), and, for comparison, also with time-dependent complete active space SCF (TD-CASSCF). Extensions to include ionization, dissipation, and to control electron dynamics by pulse shaping, will also be presented. For small systems, such as the hydrogen molecular cation, also numerically exact methods to solve the time-dependent Schrödinger equation are available. Two classes of applications will be presented. In a first one, the creation of electron wavepackets and the control of electron correlation by shaped laser pulses will be demonstrated: Here, a Hartree-Fock like single-determinant state is created by using optimal control theory. In a second class of applications, the non-linear response of molecules to ultrashort laser pulses will be examined, in particular, high harmonic generation (HHG) in molecular systems: Its control (for the hydrogen molecule) by stochastic pulse optimization, the HHG-spectroscopic distinction of polyatomic, organic molecules (cis- and trans-disubstituted ethene), and, finally, for the case of muonic hydrogenic cations exposed to ultra-intense laser pulses, the role of non-Born-Oppenheimer effects and the contribution of nuclear motion to HHG spectra.

Laser-pulse driven electron dynamics and their control treated by wave function methods

256th National Meeting (2018)

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