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Measurement of the spatial correlation function of phase fluctuating Bose-Einstein condensates
D Hellweg1, L Cacciapuoti, M Kottke
1Institut für Quantenoptik, Universität Hannover, Welfengarten 1, 30167 Hannover, Germany. hellweg@iqo.uni-hannover.de
Physical Review Letters
|August 9, 2003
Summary
Researchers measured intensity correlations in Bose-Einstein condensates to determine phase coherence. This method, similar to the Hanbury Brown and Twiss experiment, successfully confirmed the condensate
Area of Science:
- Quantum optics
- Atomic physics
- Condensed matter physics
Background:
- Bose-Einstein condensates (BECs) are quantum states of matter with unique properties.
- Understanding phase fluctuations and coherence is crucial for controlling BECs.
- The Hanbury Brown and Twiss experiment pioneered intensity interferometry for stellar measurements.
Purpose of the Study:
- To measure the phase correlation properties of phase-fluctuating Bose-Einstein condensates.
- To adapt intensity correlation techniques for characterizing condensate coherence.
- To determine the phase coherence lengths of elongated Bose-Einstein condensates.
Main Methods:
- Generating two interfering, spatially displaced copies of phase-fluctuating Bose-Einstein condensates.
- Measuring the intensity correlation function between these copies.
- Applying principles analogous to the Hanbury Brown and Twiss stellar interferometer.
Main Results:
- The measured intensity correlation function directly reflects the phase correlation properties of the initial condensate.
- Spatial intensity correlations successfully determined the phase coherence lengths of elongated condensates.
- Experimental results showed good agreement with theoretical predictions for the correlation function and coherence length.
Conclusions:
- Spatial intensity correlations provide a viable method for measuring phase coherence in Bose-Einstein condensates.
- The study validates the applicability of Hanbury Brown and Twiss-type measurements in quantum systems.
- The findings confirm the expected coherence properties of the investigated elongated condensates.
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