Decoherence and dephasing in strongly driven colliding
Bose-Einstein condensates
N. Katz, R. Ozeri, E. Rowen, E.
Gershnabel and N. Davidson
We report on a series of measurements of decoherence and wavepacket
dephasing between two colliding, strongly coupled, identical Bose-Einstein
condensates. We measure, in the strong excitation regime, a suppression of the
mean-field shift, compared to the shift which is observed for a weak
excitation. This suppression is explained by applying the Gross-Pitaevskii
energy functional. By selectively counting only the non-decohered fraction in a
time of flight image we observe oscillations for which both inhomogeneous and
Doppler broadening are suppressed, in quantitative agreement with a full
Gross-Pitaevskii equation simulation. If no post selection is used, the
decoherence rate due to collisions can be extracted, and is in agreement with
the local density average calculated rate.