Tunneling Dynamics in Open Ultracold Bosonic Systems
Tunneling Dynamics in Open Ultracold Bosonic Systems
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开放式超冷玻色子系统中的隧道动力学
DOI：
10.1007/978-3-319-07085-8
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发表时间：
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通讯作者：
Axel U. J.
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作者：
Axel U. J.
本论文研究了玻色-爱因斯坦凝聚体等多体系统的量子隧穿问题。尽管在单个粒子穿过势垒的隧穿方面做了大量的工作，但我们对由几个或多个粒子组成的系统如何穿过势垒到达开放空间知之甚少。目前的工作使用含时多玻色子薛定谔方程的数值精确解来探索超冷玻色子中隧穿到开放空间过程的丰富物理学，这些超冷玻色子最初被制备为玻色-爱因斯坦凝聚体，随后被允许隧穿通过障碍到开放空间。多体过程是由同时发生的以不同动量为特征的单粒子过程建立起来的。这些动量对应于粒子数减少的系统的化学势。多玻色子过程展示了令人兴奋的集体现象：逃逸粒子碎裂，失去了与源以及彼此之间的相干性，同时系统内建立了相关性。多体过程的详细理解是用来设计和测试一个计划，以控制最终状态，动量分布，甚至相关动力学的隧穿过程。
This thesis addresses the intriguing topic of the quantum tunnelling of many-body systems such as Bose-Einstein condensates. Despite the enormous amount of work on the tunneling of a single particle through a barrier, we know very little about how a system made of several or of many particles tunnels through a barrier to open space. The present work uses numerically exact solutions of the time-dependent many-boson Schrödinger equation to explore the rich physics of the tunneling to open space process in ultracold bosonic particles that are initially prepared as a Bose-Einstein condensate and subsequently allowed to tunnel through a barrier to open space. The many-body process is built up from concurrently occurring single particle processes that are characterized by different momenta. These momenta correspond to the chemical potentials of systems with decreasing particle number. The many-boson process exhibits exciting collective phenomena: the escaping particles fragment and lose their coherence with the source and among each other, whilst correlations build up within the system. The detailed understanding of the many-body process is used to devise and test a scheme to control the final state, momentum distributions and even the correlation dynamics of the tunneling process.