We investigate the rotational properties of a dipolar Bose-Einstein condensate trapped in a toroidal geometry. Studying the ground states in the rotating frame and at fixed angular momenta, we observe that the condensate acts in distinctly different ways depending on whether it is in the superfluid or in the supersolid phase. We find that intriguingly, the toroidal dipolar condensate can support a supersolid persistent current which occurs at a local minimum in the ground state energy as a function of angular momentum, where the state has a vortex solution in the superfluid component of the condensate. The decay of this state is prevented by a barrier that in part consists of states where a fraction of the condensate mimics solid-body rotation in a direction opposite to that of the vortex. Furthermore, we find that superfluid condensates may enter the supersolid phase when forced to take angular momentum. Last, the rotating toroidal supersolid shows hysteretic behavior that is qualitatively different depending on the superfluid fraction of the condensate.

中文翻译：

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环形双极超固体中的持续电流

我们研究了被困在环形几何体中的偶极玻色-爱因斯坦冷凝物的旋转特性。研究旋转框架和固定角动量下的基态，我们观察到冷凝物以明显不同的方式起作用，这取决于它是在超流体阶段还是在超固相阶段。我们有趣地发现，环形双极冷凝物可以支持超固态持续电流，该电流在基态能量的局部最小值处作为角动量的函数出现，其中该态在冷凝物的超流体成分中具有涡旋解。这种状态的衰减可以通过屏障来防止，该屏障部分由冷凝物的一部分模仿固体沿相反方向旋转的状态组成到漩涡的 此外，我们发现当被迫采取角动量时，超流体凝结物可能进入超固相。最后，旋转的环形超固体显示出滞后行为，该滞后行为在质量上取决于冷凝物的超流体部分。