The fundamental question inspiring this project was how initially confined quantum mechanical particles relax towards a spatially extended region. To this end we studied a hypothetical experiment, first trapping a number of such particles in a box cut off from the remainder of a large system and then observing the dynamics when freeing them in a sudden quench.

 Numerically simulating the depicted sudden quench protocol I analyzed features of the unitary relaxation of Bose-Einstein Condensates towards a spatially extended region for various forms of potentials. This lead to surprising  and unintuitive effects. For instance, the expulsion from the energetically unfavorable region is only possible up to a specific threshold for the steepness of the potential. For slopes that are higher than this threshold  the trapped particles oscillate.

To understand the dynamical trapping I then developed an analytical semi-classical model allowing a very good understanding and prediction of the trapping and also of the oscillations.

These results were published alongside other results from DMRG simulations done in my research group in a publication in Phys Rev A 86 (2012).