Creation and Stability of Vortices in a Dilute Trapped Bose Gas

9971518 fetter这笔拨款将支持理论研究，研究超流氦与由冷碱原子形成的固定和旋转玻色-爱因斯坦凝聚物之间的联系。当前该领域的主要问题之一是单连通凝结水和多连通凝结水中量子化环流的产生、稳定性和检测。这项研究将使用已知的低温下稀玻色气体的一般理论描述来研究旋转非轴对称凝聚体中产生漩涡的临界角速度，其中旋转的阱壁将角动量传递给原子，无论是在小凝聚体的接近理想极限还是在大凝聚体的相反极限。这引入了几个新的概念特性。分析将被扩展到包括在类似的双连接非轴对称凝聚中创建量子化循环。对于含有单量子化涡的非旋转轴对称凝结物，单个正态模的频率为负，表明存在潜在的不稳定性。外部旋转提高了这个频率，并最终使其为正（从而稳定了涡流）。对小型近理想凝结物中的涡旋的这种情况进行了详细的分析，其中涡旋的负频率正态模态涉及涡旋核心相对于凝结物质心的运动。用几种不同的方法研究了大型轴对称凝结水中涡旋的反极限。对旋转非轴对称凝结物的推广对于在小凝结物和大凝结物极限下产生涡的可能实验方案尤其重要。对于这种超流氦薄膜，涡线变成了简单的二维煎饼涡。这种特性使得研究具有极端轴对称的近二维凝结水中煎饼涡的特性变得非常有趣。此外，还有一个有趣的问题，即这种被困系统是否能够达到严格的二维极限。这笔拨款将支持理论研究，研究超流氦（一种无阻力流动的流体）和由冷碱原子形成的静止和旋转的玻色-爱因斯坦凝聚体之间的联系。玻色-爱因斯坦凝聚物在许多年前就被预测到，但直到最近才在实验室中被观察到。当前该领域的主要问题之一是单连通凝结水和多连通凝结水中量子化环流的产生、稳定性和检测。本研究将研究这些凝析油的各种构型

9971518FetterThis grant will support theoretical research which investigates the connections between concepts developed for superfluid helium and stationary and rotating Bose-Einstein condensates formed from cold alkali atoms. One of the major current issues in this field is the creation, stability, and detection of quantized vortices in a simply connected condensate and quantized circulation in a multiply connected condensate. This research will use the known general theoretical description of a dilute Bose gas at low tempertaure to study the critical angular velocity for the creation of a vortex in rotating nonaxisymmetric condensates, where the rotating trap walls impart angular momentum to the atom, both in the nearly ideal limit of a small condensate and in the opposite limit of a large condensate. This introduces seveal new conceptual features. The analysis will be extended to include the creation of quantized circulation in a similar doubly connected nonaxisymmetric condensate.For a nonrotating axisymmetric condensate containing a singly quantized vortex, one single normal mode has a negative frequency, which indicates a potential instability. An external rotation raises this frequency and eventually makes it positive (thus stabilizing the vortex). This situation has been analyzed in detail for a vortex in a small nearly ideal condensate, where the negative-frequency normal mode involves a motion of the vortex core relative to the center of mass of the condensate. The opposite limit of a vortex in a large axisymmetric condensate has been studied with several different methods. The proposed generalization to a rotating nonaxisymmetric condensate is especially important in connection with possible experimental schemes for vortex creation, both in the small-condensate and large-condensate limits.For this superfluid helium films, the vortex lines become simply two-dimensional pancake vortices. This behavior makes it interesting to investigate the behavior of pancake vortices in a nearly two-dimensional condensate with extreme axial symmetry. In addition, there is the intriguing question whether such trapped systems can ever attain the strict two-dimensional limit.%%%This grant will support theoretical research which investigates the connections between concepts developed for superfluid helium (a fluid which flows without resistance) and stationary and rotating Bose-Einstein condensates formed from cold alkali atoms. Bose-Einstein condensates were predicted many years ago, but only recently have been observed in the laboratory. One of the major current issues in this field is the creation, stability, and detection of quantized vortices in a simply connected condensate and quantized circulation in a multiply connected condensate. This research will study various configurations of these condensates.***