TD-2RDM for attosecond correlation dynamics

Current technological progress frequently builds on exploiting the laws of quantum mechanics. Future quantum materials and devices will be governed by the fundamental properties of quantum physics. Time- dependent systems out of equilibrium play an increasingly important role in this development. Ultrafast lasers allow to drive atoms, molecules, and nanostructures to states with new and desired properties. We know the fundamental equation governing quantum dynamics, the Schrödinger equation for the wavefunction, for almost 100 years. Unfortunately, accurate solutions of the full wavefunction for systems involving many particles are virtually impossible to find. Such solutions are, however, needed to make reliable predictions for the dynamics of quantum systems. The goal of the present project is to develop a new strategy to accurately solve the Schrödinger equation for driven quantum systems containing a large number of particles. Key to this approach is to completely avoid the determination of the notoriously complex wavefunction which depends on all involved particles and, instead, to focus on a drastically simplified object, the reduced density matrix which depends only on just two rather than all particles. Finding accurate solutions of the Schrödinger equation for this so-called two-particle reduced density matrix that are able to retain the essential information on the original many-particle system is the central aim of this project. Progress towards this goal would open up the opportunity for a wide range of applications to technologically relevant driven quantum systems.