Density fluctuations in elongated Bose gases : from the weakly to strongly interacting regimes and from 1D to 3D
Abstract
In this seminar, we will present several recent results of elongated Bose gases obtained from our atom-chip setup. Using in-situ density fluctuation measurements, we investigated in detail the quasi-condensation transition for weakly interacting gases, and the 1D-3D dimensional crossover has been clarified. We also reached the so-called quantum quasi-condensate regime where the atom number fluctuations are sub-poissonian. Finally, thanks to the use of an original AC atom guide that eliminates the roughness of the trapping potential, we were able to approach the fermionised (or strongly interacting) regime. The gas then no longer show super-poissonian fluctuations : the fluctuations, poissonian at low density become sub-poissonian at high density, as that of a Fermi gas.