Wednesday, July 15, 2009

Space-Time Sensors using Atomic Levitation

Space-Time Sensors using Multiple-Wave Atomic Levitation
Optical atomic clocks are promising tools to investigate basics physics through fundamental tests. The best clocks to date control the atomic motion by trapping the sample in an optical lattice and then interrogate the atomic transition by shining on these atoms a distinct laser of controlled frequency. In order to perform both operations simultaneously and with the same laser field, we propose to use instead the levitation of a Bose-Einstein condensate through multiple-wave atomic interferences. The levitating condensate experiences a coherent localization in momentum and a controlled diffusion in altitude. The sample levitation is bound to a set of resonance conditions used either for frequency or for acceleration measurements. The chosen vertical geometry solves the limitations imposed by the sample free fall in previous optical clocks using also atomic interferences. This configuration allows for multiple-wave interference effects, which maintain the atomic population in levitation and yield a sensitivity improvement. This setup constitutes an attractive alternative to current atomic clocks and gravimeters.