Multielectron dynamics in matter exposed to strong laser fields

Since the invention of ultrashort light pulses, very high electric field strengths have been available. Several interesting and exciting phenomena and applications as hight harmonic generation (HHG), above threshold ionization (ATI), x-ray lasing, laser machining, attosecond pulse generation, laser triggered explosion of clusters resulting in neutron production, time-resolved Coulomb explosion imaging, and strong field control of chemical processes occur when such a high power laser pulse interacts with matter. Theoretical models have played a key role in the understanding and development of the above applications. An exact quantum mechanical solution of strong field matter interaction is far beyond current computer capacities making approximations necessary. The two most commonly used simplifications are the strong field approximation (SFA) and the single active electron (SAEA) approximation. The purpose of this work is the development of a multielectron strong field (MESF) theory, based on the SFA which accounts for the correlated dynamics of the bound electrons to make a first step to understand the interplay between ionization and bound electron dynamics in complex systems. Then the MESF theory is applied to investigate the electron reconfiguration dynamics of matter during optical field ionization. We obtain analytical results which identify the parameter ranges where multielectron reconfiguration dynamics plays an important role and compare it with experimental results. In the last chapter the development of a time-dependent multi-configuration Hartree-Fock (MCTDHF) method for strong field problems is discussed. (author)