Abstract:

Laser light is characterized by the fact that all the photons are extracted from the same mode of a resonant cavity, and are coherent with one another. Since 1996, several teams have extracted coherent matter waves from a Bose-Einstein condensate (BEC), in which millions of atoms coherently occupy the same quantum state. However, such "atom lasers" always suffers from the major drawbacks of being pulsed, and of having a very low average flux of atoms, since the extraction of the matter wave leads to the depletion of the BEC.

Our team is trying to achieve a continuous and intense source of Bose-condensed matter using a different approach. We produce a continuous and ultra cold beam of Rb87 atoms. The production of this beam is based on the periodic injection of atom packets in a 4.5 meter magnetic guide. We demonstrated the first implementation of evaporative cooling on a continuous beam. Being still far from reaching the condensation threshold, we have developed several techniques in order to manipulate the atom packets propagating in the magnetic guide: by (i) slowing them with a moving magnetic mirror, (ii) trapping them in a train of magnetic traps.  We have also investigated the production and manipulation of those packets in an optical dipolar trap using a 300 W red detuned laser.