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Q: Fachverband Quantenoptik und Photonik
Q 30: Poster II
Q 30.9: Poster
Dienstag, 3. März 2009, 16:30–19:00, VMP 9 Poster
Quantum Dynamics of Spin 1 Bosons in SMA — •Jannes Heinze1, Frank Deuretzbacher1,2, and Daniela Pfannkuche1 — 1I. Institut für Theoretische Physik, Universität Hamburg, Germany — 2Mathematical Physics, Lund Institute of Technology, Sweden
We investigate the dynamics of f=1 spinor condensates using the fully quantum mechanical single-mode-approximation (SMA) model by Law et al. [PRL 81, 5257], including the quadratic Zeeman effect. This model was used by Widera et al. [PRL 96, 190405] to describe their measurements for two atoms. In this contribution, we present exact analytical results and numerical calculations for larger particle numbers N and thereby identify effects due to many-particle correlations. We discuss the behavior for different initial states and magnetic fields. For the fully stretched state where all atoms are aligned in the x-direction, we find a novel beat note phenomenon at large magnetic fields, which should be observable in experiments for small particle numbers larger than two. This beat note is a clear sign of genuine many-particle correlations. Starting from exact analytical results as well as numerical simulations of the quantum dynamics for large particle numbers, we discuss the mean field limit. The quantum dynamics are shown to converge toward the SMA mean field solution in the thermodynamic limit. That is, the many-particle correlations disappear for N→∞ and N/V constant, where V is the volume of the system. Therefore we are able to make predictions about corrections to the mean field solutions due to finite particle numbers.