Coherent manipulation of an ytterbium Bose-Einstein condensate on the "clock" transition : from spectroscopy to artificial magnetism
Alexandre Dareau (LKB)

In this thesis, we report on the construction of an experiment aimed at trapping and cooling an ytterbium gaz, in order to realize artificial magnetic fields. In the long term, this setup will allow the study of strongly correlated quantum states which are atomic analogs of integer or fractional quantum Hall systems.

We will first present the building of our experimental apparatus, and the optical cooling of ytterbium 174. In particular, we will report on the design of a Zeeman slower, allowing for the direct loading of a magneto-optical trap operated on ytterbium’s intercombination transition. The atomic cloud is then transported in an optical dipole trap. A subsequent evaporative cooling stage results in the production of Bose-Einstein condensates of about 50 000 atoms.

We then describe the construction of an ultra-narrow laser system at 578nm, able to drive ytterbium’s "clock" transition. The laser frequency is stabilized using a high-finesse Fabry-Perot cavity, whose properties are precisely characterized in this work. Specifically, we present a method to calibrate the absolute frequency of the cavity by comparison with an optical transition of molecular iodine.

Finally, we show the results of spectroscopic measurements done on ytterbium condensates using the ultra-narrow laser. We also report on the coherent manipulation of the condensate on the clock transition, consisting in the observation of Rabi oscillations. These preliminary experiments should allow for a measurement of ytterbium’s scattering properties.