vbid/9783319070858

Description

This thesis addresses the intriguing topic of the quantum tunnelling of many-body systems such as Bose-Einstein condensates. Despite the enormous amount of work on the tunneling of a single particle through a barrier, we know very little about�how a system made of several or of many particles tunnels through a barrier to open space.�The present�work uses�numerically exact solutions of the time-dependent many-boson Schr�dinger equation to explore the rich physics of the tunneling to open space process in ultracold bosonic particles that are initially prepared as a Bose-Einstein condensate and subsequently allowed to tunnel through a barrier to open space. The many-body process is built up from concurrently�occurring single particle processes that are characterized by different momenta. These momenta correspond to the chemical potentials of systems with decreasing particle number. The many-boson process exhibits exciting collective phenomena: the escaping particles�fragment and lose their coherence with the source and among each other, whilst correlations�build up�within the system. The detailed understanding of the many-body process is used to devise and test a scheme to control the final state, momentum distributions and even the correlation dynamics of the tunneling process.Typham this is the title: Tunneling Dynamics in Open Ultracold Bosonic Systems Numerically Exact Dynamics � Analytical Models � Control Schemes