Momentum spectroscopy of 1D phase fluctuations in Bose-Einstein condensates.
We measure the axial momentum distribution of Bose-Einstein condensates with an aspect ratio of 152 using Bragg spectroscopy. We observe the Lorentzian momentum distribution characteristic of one-dimensional phase fluctuations. The temperature dependence of the width of this distribution provides a quantitative test of quasicondensate theory. In addition, we observe a condensate length consistent with the suppression of density fluctuations, even when phase fluctuations are large.
Richard
S
S
Laboratoire Charles Fabry de l'Institut d'Optique, UMR 8501 du CNRS, 91403 Orsay Cedex, France.
Gerbier
F
F
Thywissen
J H
JH
Hugbart
M
M
Bouyer
P
P
Aspect
A
A