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far below the saturation intensity. In previous works π polarized light at low intensities
scatters photons from a condensate with the distribution expected from a single atom
and does not undergo either Raman or Rayleigh superradiance [44, 45, 68]. If superradiant
processes are occurring they will exhibit a nonlinear increase in atom losses with time and
intensity. Since previous studies were done off resonance a check was done to ensure that
superradiance was not occuring when we performed a scattering measurement. Fig. 4-19
shows how increasing the pulse width does not result in substantial additional losses as we
would expect for superradiance.
0
57
0
20
Photonsêpulse
114
171
228
286
80
100
1
0.8
0.6
0.4
0.2
40
60
Pulse Width HmsL
2 /τ
Figure 4-19: Expected pulsed quantum Zeno effect ( 41 δtωR
EP = 1) as a function of scattering measurement laser pulse width. Open triangles are corrected for parasitic measurement
losses.
4.3.6
Collisions
Collisions between the recoiling atoms which have been measured and the remaining condensate can cause additional losses. To estimate the effects of collisions the scattering cross
section and the duration that scattered atoms remain in the trap must be considered. When
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