Nonequilibrium kinetic theory for trapped binary condensates
Nonequilibrium kinetic theory for trapped binary condensates
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DOI：
10.1103/physreva.92.063607
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发表时间：
2015-07
影响因子：
2.9
通讯作者：
M. Edmonds;K. L. Lee;N. Proukakis
中科院分区：
文献类型：
--
作者：
M. Edmonds;K. L. Lee;N. Proukakis
我们推导出两个相互作用的原子玻色-爱因斯坦凝聚体的二元混合物的非平衡有限温度动力学理论，并用它来探索在现实的实验几何中可达到的流体力学程度。基于动力学理论的时间尺度参数的标准分离，多组分系统的凝聚体的动力学被示出为由耗散的Gross-Pitaevskii方程描述，自洽地耦合到非凝聚体原子的相应量子玻尔兹曼方程：在通常的平均场贡献之上，我们的方案确定了总共八个不同的碰撞过程，其动力学相互作用被认为是系统平衡的原因。为了提供它们的第一个特征，我们对实验上可获得的$^{87}$Rb-$^{41}$K和$^{87}$Rb-$^{85}$Rb混合物的陷阱频率和几何形状对碰撞率的作用进行了详细的数值分析，讨论了系统在何种程度上可能接近其中一些过程的流体动力学状态，作为未来超冷玻色气体混合物的实验研究的指导。
We derive a non-equilibrium finite-temperature kinetic theory for a binary mixture of two interacting atomic Bose-Einstein condensates and use it to explore the degree of hydrodynamicity attainable in realistic experimental geometries. Based on the standard separation of timescale argument of kinetic theory, the dynamics of the condensates of the multi-component system are shown to be described by dissipative Gross-Pitaevskii equations, self-consistently coupled to corresponding Quantum Boltzmann equations for the non-condensate atoms: on top of the usual mean field contributions, our scheme identifies a total of eight distinct collisional processes, whose dynamical interplay is expected to be responsible for the systems equilibration. In order to provide their first characterization, we perform a detailed numerical analysis of the role of trap frequency and geometry on collisional rates for experimentally accessible mixtures of $^{87}$Rb-$^{41}$K and $^{87}$Rb-$^{85}$Rb, discussing the extent to which the system may approach the hydrodynamic regime with regard to some of those processes, as a guide for future experimental investigations of ultracold Bose gas mixtures.