TY  - GEN
CY  - Heidelberg
AV  - public
Y1  - 2013/06//
TI  - Tunneling Dynamics in Open Ultracold Bosonic Systems
ID  - heidok15049
A1  - Lode, Axel U. J.
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/15049/
N2  - This thesis explores the quantum many-body tunneling dynamics of open ultracold bosonic systems with the recently developed multiconfigurational time-dependent Hartree for bosons (MCTDHB) method. The capabilities of MCTDHB to provide solutions to the full time-dependent many-body problem are assessed in a benchmark using the analytically solvable harmonic interaction Hamiltonian
and a generalization of it with time-dependent both one- and two-body potentials. In a comparison with numerically exact MCTDHB results, it is shown that e.g. lattice methods fail qualitatively to describe the tunneling dynamics. A
model assembling the many-body physics of the process from basic simultaneously happening single-particle processes is derived and verified with a numerically exact MCTDHB description. The generality of the model is demonstrated
even for strong interactions and large particle numbers. The ejection of the bosons from the source occurs with characteristic velocities. These velocities are
defined by the chemical potentials of systems with different particle numbers which are converted to kinetic energy. The tunneling process is accompanied by fragmentation: the ejected bosons lose their coherence with the source and among each other. It is shown that the various aspects of the tunneling dynamics? can be controlled well with the interaction and the potential threshold.
ER  -