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

TL;DR

This paper investigates how attractive interactions between a Fermi gas and a Bose-Einstein condensate influence the expansion dynamics and spatial distribution, revealing mutual attraction effects and bimodal momentum distributions.

Contribution

It provides new insights into the expansion behavior of Fermi gases interacting with BECs, highlighting the impact of interspecies attraction on dynamics and distribution during expansion.

Findings

Interspecies attraction slows the expansion of the Fermi gas.

Bimodal momentum distribution observed for large atom numbers.

Mutual attraction influences the spatial distribution during initial expansion.

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.