Bragg spectroscopy of a strongly interacting 85Rb Bose-Einstein condensate.
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.
Papp
S B
SB
JILA, Quantum Physics Division, National Institute of Standards and Technology and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA.
Pino
J M
JM
Wild
R J
RJ
Ronen
S
S
Wieman
C E
CE
Jin
D S
DS
Cornell
E A
EA