Dipolar Fermi gases in anisotropic traps
Dipolar Fermi gases in anisotropic traps
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DOI：
10.1103/physreva.81.063629
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发表时间：
2010-03
影响因子：
2.9
通讯作者：
Aristeu R P Lima;A. Pelster
中科院分区：
文献类型：
--
作者：
Aristeu R P Lima;A. Pelster
量子简并费米气体通过各向异性和长程偶极相互作用的研究是冷原子研究中一个令人兴奋和快速发展的分支。最近的实验进展捕获，冷却和控制极性分子与大电偶极矩，因此，激励了许多理论上的努力。在最近的一封信中，我们简要地讨论了应用变分含时Hartree-Fock方法，从理论上研究了柱对称谐波陷阱中这样一个系统的静态和动态性质。我们集中在流体动力学制度，碰撞确保局部平衡。在这里，我们提出了一个详细的理论扩展到包括一般情况下的谐波陷阱的几何形状没有任何对称性。在推导出气体的运动方程后，我们探索了它们的静态解，以研究真实的和动量空间中的纵横比以及稳定性图等关键特性。我们发现，尽管缺乏对称性的陷阱，动量分布保持圆柱对称。然后，运动方程被用来研究低洼的流体动力学激励，其中，除了四极和双极模式，径向四极模式也进行了研究。此外，我们还研究了飞行时间动力学，因为它是量子气体的重要诊断工具。我们发现实空间的纵横比在展开过程中是颠倒的，而在动量空间中的纵横比则是渐近一致的。此外，偶极-偶极相互作用的各向异性特征进行了详细讨论。这些结果可能是特别有用的强偶极异质极性分子深入量子简并制度的未来调查。«少
The quest for quantum degenerate Fermi gases interacting through the anisotropic and long-range dipole-dipole interaction is an exciting and fast developing branch within the cold-atom research program. Recent experimental progress in trapping, cooling, and controlling polar molecules with large electric dipole moments has, therefore, motivated much theoretical effort. In a recent letter, we have briefly discussed the application of a variational time-dependent Hartree-Fock approach to study theoretically both the static and the dynamic properties of such a system in a cylinder-symmetric harmonic trap. We focused on the hydrodynamic regime, where collisions ensure the equilibrium locally. Here we present a detailed theory extended to encompass the general case of a harmonic trap geometry without any symmetry. After deriving the equations of motion for the gas, we explore their static solutions to investigate key properties like the aspect ratios in both real and momentum space as well as the stability diagram. We find that, despite the lack of symmetry of the trap, the momentum distribution remains cylinder symmetric. The equations of motion are then used to study the low-lying hydrodynamic excitations, where, apart from the quadrupole and monopole modes, the radial quadrupole mode is also investigated. Furthermore, we study the time-of-flight dynamicsmore » as it represents an important diagnostic tool for quantum gases. We find that the real-space aspect ratios are inverted during the expansion, while that in momentum space becomes asymptotically unity. In addition, anisotropic features of the dipole-dipole interaction are discussed in detail. These results could be particularly useful for future investigations of strongly dipolar heteronuclear polar molecules deep in the quantum degenerate regime.« less