Hannover 2003 – scientific programme
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Q: Quantenoptik
Q 27: Poster: Quantengase
Q 27.9: Poster
Tuesday, March 25, 2003, 16:30–18:30, Lichthof
Interferometric measurements with phase fluctuating Bose-Einstein condensates — •D. Hellweg1, M. Kottke1, T. Schulte1, S. Drenkelforth1, L. Cacciapuoti1, K. Sengstock2, J.J. Arlt1, and W. Ertmer1 — 1Institut für Quantenoptik, Universität Hannover, Welfengarten 1, 30167 Hannover — 2Institut für Laserphysik, Universität Hamburg, Jungiusstr. 9, 20355 Hamburg
The fascinating properties of Bose-Einstein condensates are in many respects strikingly different from those of thermal atoms. Many of these fundamental differences result from the macroscopic occupation of a single quantum state and the existence of a macroscopic phase. Promising applications of Bose-Einstein condensates, such as their use as a source for atom lasers and interferometric measurements rely on the coherence properties of these ensembles.
We present detailed studies of the phase correlation properties of elongated BECs. It will be shown that at finite temperature the condensate phase is not uniform but undergoes statistical fluctuations with an average value depending on the system parameters. The influence of phase fluctuations on interferometric measurements is shown and these measurements are used to observe the spatial coherence of the sample. Our results set important limitations for the use of very elongated BECs such as they are typically produced by microtrap experiments for phase-sensitive measurements.