TY  - GEN
KW  - Bose-Einstein condensation 
KW  -  nonlinear dynamics 
KW  -  double well potential 
KW  -  selftrapping 
KW  -  Josephson junction
ID  - heidok5869
N1  - Teile in: Physical Review Letters, 95(010402), 2005
Y1  - 2005///
TI  - Observation of nonlinear tunneling of a Bose-Einstein condensate in a single Josephson junction
AV  - public
N2  - In this thesis, I present the first experimental implementation of a Josephson junction for Bose-Einstein condensates. The weak link between two BECs constitutes the nonlinear generalization of the well known Josephson junction of weakly-coupled superconductors that are separated by a thin insulating barrier. In our experiment, the required overlap of two macroscopic wavefunctions is provided by loading a BEC into an optical double well potential. It is realized by a superposition of a one-dimensional optical lattice with a focused laser beam optical dipole trap. The tunneling dynamics between the two potential wells exhibits two distinct dynamical regimes. For small initial population imbalances of the two wells we observe nearly sinusoidal Josephson tunneling oscillations, which are characterized by an oscillating population and relative phase. The situation changes drastically, if the initial population imbalance is chosen above a critical value. In this case, resonant tunneling between the two wells is prohibited because the difference between the on-site particle interaction energies in the two wells exceeds the tunneling energy splitting. As a consequence, the atomic distribution becomes self-locked and the relative phase evolves unbound in time. This regime of prohibited tunneling, which has no analogon in superconducting Josephson junctions, is called ?macroscopic quantum self-trapping?.
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/5869/
A1  - Albiez, Michael
ER  -