论文标题
临界速度和在点状电势中的超氟的逮捕
Critical Velocity and Arrest of a Superfluid in a Point-Like Disordered Potential
论文作者
论文摘要
超过潜在障碍的超流量流是超速bose气体的一个精心研究的问题，但是，较少的研究考虑了通过无序潜力流动的情况。在这里，我们考虑了一个超级流体流过包含多点样屏障的通道的情况，该通道随机放置以形成无序电位。首先，我们确定两个点状障碍的相对位置与这种布置的临界速度之间的关系。然后，我们表明，具有两个障碍的系统的临界速度与具有大量障碍的系统之间存在映射。通过通过点状的电位势能建立初始的超级流，比临界速度更快地移动，我们研究了如何通过涡流的成核和超流体的分解来捕捉超流，这是与量子湍流和变形的有趣联系的问题。我们将涡旋衰减速率计算为屏障的宽度增加，并表明涡旋固定成为这些较大障碍物的更重要效果。
Superfluid flow past a potential barrier is a well studied problem in ultracold Bose gases, however, fewer studies have considered the case of flow through a disordered potential. Here we consider the case of a superfluid flowing through a channel containing multiple point-like barriers, randomly placed to form a disordered potential. We begin by identifying the relationship between the relative position of two point-like barriers and the critical velocity of such an arrangement. We then show that there is a mapping between the critical velocity of a system with two obstacles, and a system with a large number of obstacles. By establishing an initial superflow through a point-like disordered potential, moving faster than the critical velocity, we study how the superflow is arrested through the nucleation of vortices and the breakdown of superfluidity, a problem with interesting connections to quantum turbulence and coarsening. We calculate the vortex decay rate as the width of the barriers is increased, and show that vortex pinning becomes a more important effect for these larger barriers.
