[Show abstract][Hide abstract] ABSTRACT: We predict the resonance-enhanced magnetic field dependence of atom-dimer relaxation and three-body recombination rates in a Rb87 Bose-Einstein condensate close to 1007G . Our exact treatments of three-particle scattering explicitly include the dependence of the interactions on the atomic Zeeman levels. The Feshbach resonance distorts the entire diatomic energy spectrum, causing interferences in both loss phenomena. Our two independent experiments confirm the predicted recombination loss over a range of rate constants that spans four orders of magnitude.
Physical Review A 01/2007; 75(2). · 3.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We manipulate a Bose-Einstein condensate using the optical trap created by
the diffraction of a laser beam on a fast ferro-electric liquid crystal spatial
light modulator. The modulator acts as a phase grating which can generate
arbitrary diffraction patterns and be rapidly reconfigured at rates up to 1 kHz
to create smooth, time-varying optical potentials. The flexibility of the
device is demonstrated with our experimental results for splitting a
Bose-Einstein condensate and independently transporting the separate parts of
the atomic cloud.
Physical Review A 12/2005; 73:031402. · 3.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Trapping and manipulation of cold atoms using optical potentials require the ability to generate and control a time varying light intensity distribution. Such an application demands that fast changing intensity distributions are generated, which are however free from flickering, or noise in general. Ferroelectric spatial light modulators are good candidates to achieve this because of their high refresh rate but they suffer from noise due to changes in the state of individual pixels during an animated sequence. A direct binary search based optimization routine was developed which minimizes the noise during such sequences. Filter sequences designed using this technique have been tested experimentally and the results demonstrated that flicker noise was eliminated.
Journal of Modern Optics 09/2004; 51(14):2235-2240. · 1.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We report the implementation of a two-dimensional Raman cooling scheme using sequential excitations along the orthogonal axes. Using square pulses, we have cooled a cloud of ultracold Cesium atoms down to an RMS velocity spread of 0.39(5) recoil velocity, corresponding to an effective temperature of 30 nK (0.15 T_rec). This technique can be useful to improve cold atom atomic clocks, and is particularly relevant for clocks in microgravity. Comment: 8 pages, 6 figures, submitted to Phys. Rev. A