Zwierlein M W, Stan C A, Schunck C H, Raupach S M F, Kerman A J, Ketterle W
Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2004 Mar 26;92(12):120403. doi: 10.1103/PhysRevLett.92.120403. Epub 2004 Mar 25.
We have observed Bose-Einstein condensation of pairs of fermionic atoms in an ultracold 6Li gas at magnetic fields above a Feshbach resonance, where no stable 6Li2 molecules would exist in vacuum. We accurately determined the position of the resonance to be 822+/-3 G. Molecular Bose-Einstein condensates were detected after a fast magnetic field ramp, which transferred pairs of atoms at close distances into bound molecules. Condensate fractions as high as 80% were obtained. The large condensate fractions are interpreted in terms of preexisting molecules which are quasistable even above the two-body Feshbach resonance due to the presence of the degenerate Fermi gas.
我们在高于费什巴赫共振的磁场下，于超冷6Li气体中观测到了费米子原子对的玻色-爱因斯坦凝聚，在真空中不存在稳定的6Li2分子的这种情况下。我们精确测定共振位置为822±3高斯。在快速磁场斜坡之后检测到了分子玻色-爱因斯坦凝聚体，该斜坡将近距离的原子对转移成束缚分子。获得了高达80%的凝聚分数。大的凝聚分数可根据预先存在的分子来解释，由于简并费米气体的存在，这些分子即使在两体费什巴赫共振之上也是准稳定的。
