Abstract
We report on measurements of the excitation spectrum of a strongly interacting Bose-Einstein condensate. A magnetic-field Feshbach resonance is used to tune atom-atom interactions in the condensate and to reach a regime where quantum depletion and beyond mean-field corrections to the condensate chemical potential are significant. We use two-photon Bragg spectroscopy to probe the condensate excitation spectrum; our results demonstrate the onset of beyond mean-field effects in a gaseous Bose-Einstein condensate.
- Received 9 April 2008
DOI:https://doi.org/10.1103/PhysRevLett.101.135301
©2008 American Physical Society
Synopsis
Boosting interactions in BECs
Published 22 September 2008
Tuning the interactions between ultracold atoms leads to a strongly interacting superfluid with properties more akin to liquid helium than a dilute Bose-Einstein condensate.
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