Klauss Catherine E, Xie Xin, Lopez-Abadia Carlos, D'Incao José P, Hadzibabic Zoran, Jin Deborah S, Cornell Eric A
JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, Boulder, Colorado 80309-0440, USA.
Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
Phys Rev Lett. 2017 Oct 6;119(14):143401. doi: 10.1103/PhysRevLett.119.143401. Epub 2017 Oct 5.
We convert a strongly interacting ultracold Bose gas into a mixture of atoms and molecules by sweeping the interactions from resonant to weak. By analyzing the decay dynamics of the molecular gas, we show that in addition to Feshbach dimers it contains Efimov trimers. Typically around 8% of the total atomic population is bound into trimers, identified by their density-independent lifetime of about 100 μs. The lifetime of the Feshbach dimers shows a density dependence due to inelastic atom-dimer collisions, in agreement with theoretical calculations. We also vary the density of the gas across a factor of 250 and investigate the corresponding atom loss rate at the interaction resonance.
我们通过将相互作用从共振态调节到弱相互作用态，把强相互作用的超冷玻色气体转化为原子与分子的混合物。通过分析分子气体的衰变动力学，我们发现除了费什巴赫二聚体之外，它还包含埃菲莫夫三聚体。通常，约8%的总原子数会束缚形成三聚体，其特征是具有约100 μs的与密度无关的寿命。由于非弹性原子 - 二聚体碰撞，费什巴赫二聚体的寿命表现出密度依赖性，这与理论计算结果相符。我们还将气体密度改变了250倍，并研究了相互作用共振时相应的原子损失率。
