Universality of fragmentation in the Schrödinger dynamics of bosonic Josephson junctions
Universality of fragmentation in the Schrödinger dynamics of bosonic Josephson junctions
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DOI：
10.1103/physreva.89.023602
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发表时间：
2012-07
影响因子：
2.9
通讯作者：
K. Sakmann;A. Streltsov;O. Alon;L. Cederbaum
中科院分区：
文献类型：
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作者：
K. Sakmann;A. Streltsov;O. Alon;L. Cederbaum
对一维玻色子约瑟夫森结的多体薛定谔动力学进行了长达10000个玻色子的长时间研究。初始态是完全凝聚的，相互作用强度较弱。我们在多体水平上报道了一个普遍的碎裂动力学：由不同数量的粒子在恒定的平均场相互作用强度下碎裂成相同的值的系统。这一现象表现在系统的关联函数等可观测性中。我们基于玻色-哈伯德模型解析地解释了这种普遍的碎裂动力学。我们由此表明，多体效应在以后变得重要的程度主要取决于初始状态。即使对于任意大的粒子数和任意弱的相互作用强度，动力学也是多体的，碎裂是普遍存在的。在Gross-Pitaevskii平均场长期有效的情况下，不存在弱相互作用极限。
The many-body Schr\"odinger dynamics of a one-dimensional bosonic Josephson junction is investigated for up to 10 000 bosons and long times. The initial states are fully condensed and the interaction strength is weak. We report on a universal fragmentation dynamics on the many-body level: systems consisting of different numbers of particles fragment to the same value at constant mean-field interaction strength. The phenomenon manifests itself in observables such as the correlation functions of the system. We explain this universal fragmentation dynamics analytically based on the Bose-Hubbard model. We thereby show that the extent to which many-body effects become important at later times depends crucially on the initial state. Even for arbitrarily large particle numbers and arbitrarily weak interaction strength the dynamics is many-body in nature and the fragmentation universal. There is no weakly interacting limit where the Gross-Pitaevskii mean field is valid for long times.