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arXiv 1503.08302cond-mat.quant-gas
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非量化angular momentum的持续电流

Persistent currents with non-quantized angular momentum

A. Muñoz Mateo, A. Gallemí, M. Guilleumas, R. Mayol

摘要:

我们分析了超冷气体在环中的玻色-爱因斯坦凝聚体中持续电流的产生。最近在实验[Nature \textbf{506},200(2014)]中研究了这种现象,其中在通过旋转弱连接激活量化持续电流中观察到磁滞回线。在这项工作中,我们证明了非量子化的角动量的三维稳态电流的存在。它们是由孤波族产生的,孤波族显示出角动量的连续变化,并在不同的缠绕数之间提供桥梁。我们发现,磁滞回线的大小是由孤立波的弱连接区域内配置的能量障碍,防止相位滑移的存在范围。当临界旋转导致绕组数和孤子态匹配时,势垒消失。在这一点上,相位滑移的朗道和费曼准则满足:流体流动达到局部声速,并且可以在系统内部激发静止的涡旋线(这是孤子的构建块)。

英文摘要:

We analyze the generation of persistent currents in Bose-Einstein condensates of ultracold gases confined in a ring. This phenomenon has been recently investigated in an experiment [Nature \textbf{506}, 200 (2014)], where hysteresis loops have been observed in the activation of quantized persistent currents by rotating weak links. In this work, we demonstrate the existence of 3D stationary currents with non-quantized angular momentum. They are generated by families of solitary waves that show a continuous variation in the angular momentum, and provide a bridge between different winding numbers. We show that the size of hysteresis loops is determined by the range of existence within the weak link region of solitary waves which configure the energy barrier preventing phase slips. The barrier vanishes when the critical rotation leads winding numbers and solitonic states to a matching configuration. At this point, Landau and Feynman criteria for phase slips meet: the fluid flow reaches the local speed of sound, and stationary vortex lines (which are the building blocks of solitons) can be excited inside the system.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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