Expansion of a Fermi gas interacting with a Bose-Einstein condensate

Abstract

We study the expansion of an atomic Fermi gas interacting attractively with a Bose-Einstein condensate. We find that the interspecies interaction affects dramatically both the expansion of the Fermi gas and the spatial distribution of the cloud in trap. We observe indeed a slower evolution of the radial-to-axial aspect ratio which reveals the importance of the mutual attraction between the two samples during the first phase of the expansion. For large atom numbers, we also observe a bimodal momentum distribution of the Fermi gas, which reflects directly the distribution of the mixture in trap. This effect allows us to extract information on the dynamics of the system at the collapse.