Research objectives and content
The proposed research belongs to the field of atom manipulation and quantum statistical effects in ultracold atomic gases. In 1995, after a 15 year-long quest, Bose-Einstein condensation (BEC) in an atomic gas was achieved. BEC was reached by evaporatively cooling atoms in a magnetic trap. The sample was prepared for evaporation by a subtle combination of laser cooling and trapping techniques.
Bose condensed atoms are coherent matter waves. The observation of BEC therefore opens up a fascinating domain of physics, possibly with important applications.
We plan to explore three promising directions: the study of elementary excitations of a condensed system, the interference of two condensates and the interaction of a condensate with a radio-frequency radiation. The applicant has made significant first steps in all of these areas. On the experimental side, we aim first at producing a condensate of cesium atoms, which is a very open question. Recently, the host laboratory cooled cesium through evaporation in a magnetic trap and with Raman cooling in a far detuned laser trap. Both approaches lead so far to a promising factor of 50 phase-space density increase over the value achievable in a magneto-optical trap.
The production of condensates with an "all-optical" method represents a important step towards applications of these quantum degenerate svstems, it might also enable us to study fermionic systems.
Finally, bv optical manipulation of Bose condensates with laser traps. intend to make a contin- uous source of coherent matter waves the atomic analog of a laser.
Training content (objective, benefit and expected impact)
The applicant, during his PhD, was a key contributor to the success of the MIT team, one of the groups which first observed BEC. His group produces condensates with up to 10 sodium atoms. Such a large number of coherent atoms facilitates the investigation of quantum effects on a macroscopic scale. Similarly, the host laboratory has played a major role in the development of laser cooling and trapping techniques. Links with industry / industrial relevance (22)
Applications include improved atomic clocks and novel atom interferometers (gyroscopes, gravime- ters) with medium term industrial relevance. as well as atom lasers.