Extending the understanding of Bose-Einstein condensate (BEC) physics to new geometries and topologies has a long and varied history in ultracold atomic physics. One such new geometry is that of a bubble, where a condensate would be confined to the surface of an ellipsoidal shell. Study of this geometry would give insight into new collective modes, self-interference effects, topology-dependent vortex behavior, dimensionality crossovers from thick to thin shells, and the properties of condensates pushed into the ultradilute limit. Here we propose to implement a realistic experimental framework for generating shell-geometry BEC using radiofrequency dressing of magnetically trapped samples. Such a tantalizing state of matter is inaccessible terrestrially due to the distorting effect of gravity on experimentally feasible shell potentials. The debut of an orbital BEC machine (NASA Cold Atom Laboratory, aboard the International Space Station) has enabled the operation of quantum-gas experiments in a regime of perpetual freefall, and thus has permitted the planning of microgravity shell-geometry BEC experiments. We discuss specific experimental configurations, applicable inhomogeneities and other experimental challenges, and outline potential experiments.

中文翻译：

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微重力玻色-爱因斯坦凝聚体的壳势。

将对玻色-爱因斯坦凝聚 (BEC) 物理学的理解扩展到新的几何形状和拓扑，在超冷原子物理学中有着悠久而多样的历史。一种这样的新几何形状是气泡，其中冷凝物将被限制在椭圆壳的表面。对这种几何形状的研究将深入了解新的集体模式、自干扰效应、依赖于拓扑的涡旋行为、从厚壳到薄壳的维数交叉，以及被推到超稀极限的冷凝物的性质。在这里，我们建议实施一个现实的实验框架，使用磁性捕获样品的射频修整来生成壳几何 BEC。由于重力对实验可行的壳势的扭曲效应，这种诱人的物质状态在陆地上是无法接近的。轨道 BEC 机器（国际空间站上的美国宇航局冷原子实验室）的首次亮相使量子气体实验能够在永久自由落体状态下进行，从而允许规划微重力壳几何 BEC 实验。我们讨论了具体的实验配置、适用的不均匀性和其他实验挑战，并概述了潜在的实验。