We report on experiments in $^6$Li Fermi gases near Feshbach resonances. A broad $s$-wave resonance is used to form a Bose-Einstein condensate of weakly bound $^6$Li$_2$ molecules in a crossed optical trap. The measured molecule-molecule scattering length of $170^{+100}_{-60}$\,nm at 770\,G is found in good agreement with theory. The expansion ener...
Cette thèse s'inscrit dans la thématique des collisions et des interactions impliquant des atomes et des molécules ultrafroids de césium. Ces travaux ont un lien étroit avec les différents domaines que sont la condensation de Bose-Einstein atomique et moléculaire, les atomes de Rydberg, les plasmas froids et l'information quantique.
Trois expérience...
Cette thèse présente l'étude théorique et expérimentale de la mise en forme et de la caractérisation d'impulsions courtes dans l'ultraviolet ainsi que l'utilisation du façonnage pour le contrôle cohérent de systèmes simples. Trois grandes directions ont été suivies, dans un premier temps, nous présentons les caractéristiques et le fonctionnement d'...
The development of various techniques to control both the internal and external degrees of freedom of molecules and to produce (ultra-) cold, trapped molecular ensembles open various avenues to physics and chemistry in the low temperature regime. These include many territories in physics like, quantum phases of matter, quantum information processin...
The interparticle interactions in ultracold atomic gases can be tuned using Fano-Feshbach scattering resonances, which occur in low-energy collisions between two atoms. These resonances are usually obtained using an external static magnetic field. They turn ultracold atomic gases into an experimental playground for the investigation of novel phases...
Published in Journal of Molecular Spectroscopy
We report on the production, deceleration and detection of a SrF molecular beam. The molecules are captured from a supersonic expansion and are decelerated in the X2Σ+(v=0,N=1) state. We demonstrate the removal of up to 40% of the kinetic energy with a 2m long modular traveling-wave decelerator. Our results demonstrate a crucial step towards the pr...
Ce travail porte sur l’étude et la réalisation d’une nouvelle technique de décélération d’un jet supersonique de particules paramagnétiques en utilisant une onde de champ magnétique progressive co-mobile. Cette technique repose sur une méthode de ralentissement basée sur les forces de type Stern Gerlach agissant sur un système paramagnétique en mou...
Published in Journal of Molecular Spectroscopy
We propose measurements of v,N=0,0→(1,0) transition frequencies of alkali earth-alkali diatomic molecules and alkali earth-hydride molecular ions. We show that the vibrational transitions considered here are useful for detecting a possible variation in the proton-electron mass ratio, possibly at the 10-16 sensitivity level. In the experiments, cold...
Published in EPJ Techniques and Instrumentation
A detailed description of a merged beam apparatus for the study of low energy molecular scattering is given. This review is intended to guide any scientist who plans to construct a similar experiment, and to provide some inspiration in describing the approach we chose to our goal. In our experiment a supersonic expansion of paramagnetic particles i...
Published in EPJ Techniques and Instrumentation
The Stark deceleration technique can produce molecular beams with very low velocities. In order to maximize the density of decelerated molecules, experimental parameters such as the velocity, the velocity spread and the spatial spread of the initial molecular beam as well as the operation characteristics of the decelerator have to be chosen appropr...
