arXiv subjects
Publications and source records attributed to Wilbert Rooijakkers.
We describe how to realize magnetic and magneto-optical confinement of ultracold atoms in a torus with adjustable diameter and how an elliptical cloud of ultracold atoms can be adiabatically transformed to have a toroidal shape. An experiment with cold 87Rb atoms demonstrates the feasibility of shape transformations. These techniques can be used for atom interferometry and quantum computation.
We demonstrate the bi-directional propagation of more than 10 7 atoms (87 Rb) around a "stadium" shaped magnetic ring that encloses an area of 10.9 cm 2, with a flux density exceeding 10 11 atoms sec -1 cm -2 . Atoms are loaded into the guide from a 2D + MOT at one side of the "stadium". An optical standing wave pulse is applied to increase the propagation velocity of atoms along the waveguide. The atom sample fills the entire ring in 200 ms when counterpropagating atom sections of the original atom cloud recombine at their initial positions after a full revolution. We discuss a possible extension of this result to a guided atom ring interferometer.
We have studied the spatial and temporal dynamics of a cold atom cloud in the conservative force field of a ferromagnetic guide, after laser cooling has been switched off suddenly. We observe outgoing 'waves' that correspond to caustics of individual trajectories of trapped atoms. This provides detailed information on the magnetic field, the energy distribution and the spin states.