Breaking of Josephson junction oscillations and onset of quantum turbulence in Bose-Einstein condensates
Breaking of Josephson junction oscillations and onset of quantum turbulence in Bose-Einstein condensates
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玻色-爱因斯坦凝聚中约瑟夫森结振荡的破坏和量子湍流的开始
DOI：
10.1088/1751-8121/ab7ad0
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Griffin A
中科院分区：
文献类型：
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作者：
Griffin A
我们分析了二维玻色-爱因斯坦凝聚体中的量子湍流的形成和动力学与约瑟夫森结势垒建模使用Gross-Pitaevskii方程。我们发现，一个足够高的初始超流密度不平衡导致随机化的动态和湍流的产生，即，形成一个准一维色散冲击组成的一列灰色孤子，最终分裂成链的不同的量化涡交替涡随机湍流流动。约瑟夫森结势垒允许我们创建两个湍流制度：声学湍流的一侧和涡流湍流的其他。在整个动力学，混合这两个制度的一个关键机制是通过障碍的涡旋偶极子的传输：我们分析这个散射过程中的障碍参数，声发射和涡旋湮灭。最后，我们讨论了涡流湍流如何演变很长一段时间，提出了最佳的配置密度不平衡和障碍高度，以创建所需的湍流制度，持续尽可能长的时间。
We analyse the formation and the dynamics of quantum turbulence in a two-dimensional Bose–Einstein condensate with a Josephson junction barrier modeled using the Gross–Pitaevskii equation. We show that a sufficiently high initial superfluid density imbalance leads to randomisation of the dynamics and generation of turbulence, namely, the formation of a quasi-1D dispersive shock consisting of a train of grey solitons that eventually breakup into chains of distinct quantised vortices of alternating vorticity followed by random turbulent flow. The Josephson junction barrier allows us to create two turbulent regimes: acoustic turbulence on one side and vortex turbulence on the other. Throughout the dynamics, a key mechanism for mixing these two regimes is the transmission of vortex dipoles through the barrier: we analyse this scattering process in terms of the barrier parameters, sound emission and vortex annihilation. Finally, we discuss how the vortex turbulence evolves for long times, presenting the optimal configurations for the density imbalance and barrier height in order to create the desired turbulent regimes which last as long as possible.