Dynamical thermalization and vortex formation in stirred two-dimensional Bose-Einstein condensates
Dynamical thermalization and vortex formation in stirred two-dimensional Bose-Einstein condensates
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搅拌二维玻色-爱因斯坦凝聚中的动态热化和涡流形成
DOI：
10.1103/physreva.78.063601
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发表时间：
2008
影响因子：
2.9
通讯作者：
C. Gardiner
中科院分区：
文献类型：
--
作者：
T. Wright;R. Ballagh;Ashton S. Bradley;P. B. Blakie;C. Gardiner
我们提出了一个量子力学处理的玻色-爱因斯坦凝聚体的机械搅拌使用经典场技术。在我们的方法中，凝聚体和激发模式使用哈密顿经典场方法，其中原子数和（旋转框架）的能量是严格守恒的。我们模拟了T=0的准二维凝聚体受旋转各向异性囚禁势扰动。初始态的真空涨落提供了一种不可约的机制，打破了凝聚态的初始对称性，并引发了随后的动力学不稳定性。高度湍流运动的发展，我们量化的出现旋转的热分量，提供必要的冷凝物中的涡旋的成核和运动阻尼的耗散。没有观察到涡旋晶格的形成，而是涡旋聚集成空间无序的涡旋液态。我们讨论的方法，我们已经开发出一个不规则分布的涡流的存在下，确定的热力学参数的热分量，并提取阻尼率从经典的场轨迹的冷凝物。
We present a quantum-mechanical treatment of the mechanical stirring of Bose-Einstein condensates using classical field techniques. In our approach the condensate and excited modes are described using a Hamiltonian classical field method in which the atom number and (rotating frame) energy are strictly conserved. We simulate a T=0 quasi-two-dimensional condensate perturbed by a rotating anisotropic trapping potential. Vacuum fluctuations in the initial state provide an irreducible mechanism for breaking the initial symmetries of the condensate and seeding the subsequent dynamical instability. Highly turbulent motion develops and we quantify the emergence of a rotating thermal component that provides the dissipation necessary for the nucleation and motional damping of vortices in the condensate. Vortex lattice formation is not observed, rather the vortices assemble into a spatially disordered vortex liquid state. We discuss methods we have developed to identify the condensate in the presence of an irregular distribution of vortices, determine the thermodynamic parameters of the thermal component, and extract damping rates from the classical field trajectories.