Figure: the vacuum chamber

BEC of Li₂ molecules

Our team at the Institute for Experimental Physics at Innsbruck University has achieved Bose-Einstein Condensation of more than 10⁵ Li₂ molecules. Starting point is a spin mixture of fermionic lithium 6 atoms in an optical dipole trap. The molecules are formed by three-body recombination during forced evaporative cooling near a Feshbach resonance. By further evaporative cooling the molecules finally condense into a thermal equilibrium state with a long lifetime of about 20 seconds. We measure the characteristic frequency of a collective excitation mode and demonstrate the magnetic-field dependent mean field. Our results are published on November 13th 2003 in Science Express.

Science 302, 2101 (2003); published online 13 Nov 2003 (10.1126/science.1093280)