Experimental study of the BEC-BCS crossover region in lithium 6

Phys Rev Lett. 2004 Jul 30;93(5):050401. doi: 10.1103/PhysRevLett.93.050401. Epub 2004 Jul 27.

Abstract

We report Bose-Einstein condensation of weakly bound 6Li2 molecules in a crossed optical trap near a Feshbach resonance. We measure a molecule-molecule scattering length of 170(+100)(-60) nm at 770 G, in good agreement with theory. We study the 2D expansion of the cloud and show deviation from hydrodynamic behavior in the BEC-BCS crossover region.