Hannover 2013 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 15: Matter-wave optics

Q 15.6: Talk

Monday, March 18, 2013, 18:00–18:15, F 142

Physical insights into the time-dependent Thomas-Fermi approximation for Bose-Einstein Condensates — •Vincenzo Tamma, Wolfgang Zeller, Enno Giese, Stephan Kleinert, Albert Roura, Wolfgang P. Schleich, and the QUANTUS Team — Institut für Quantenphysik, Universität Ulm

We unravel the physical properties of the time-dependent Thomas-Fermi (TF) regime [1] describing the time evolution of an expanding BEC for an at most quadratic potential. In particular, we study in such a regime the time evolution behavior of the phase and of the modulus of the wave function. We provide physical insight into the validity of the TF approximation depending on the experimental conditions. At the same time we apply perturbation theory in order to obtain corrections to both the phase and modulus that are relevant in different experimental situations. The obtained results have important applications in experiments exploiting long-time BEC evolution leading to interferometry and, in particular, in the experiments performed within the QUANTUS collaboration measuring quantum interference of BEC in microgravity [2].

The QUANTUS project is supported by the German Space Agency DLR with funds provided by the Federal Ministry of Economics and Technology (BMWi) under grant number 50WM1136.

[1] Y. Castin and R. Dum, Phys. Rev. Lett. 77, 5315 (1996).

[2] T. van Zoest et al., Science 328, 1540 (2010).