为了求解多玻色子薛定谔方程,我们采用了多组态含时Hartree方法(MCTDHB)。为了能够攻击更大的系统和/或传播更长时间的解决方案,我们实现了MCTDHB方法的并行版本,从而实现了最近提出的[Streltsov { \it et al.} arXiv:0910.2577v1]提出了如何有效地构造哈密顿量对玻色子态矢量作用的结果的新思想。研究了三势阱周期势中N=12,51和3003玻色子组成的排斥玻色子系统的实空间动力学。该系统的基态是三重碎裂的。通过突然强烈扭曲陷阱势,系统执行复杂的多体量子动力学。在很长一段时间内,它揭示了一种倾向,围绕一个三重分裂状态的振荡行为。这些振荡被量子损耗强烈抑制和阻尼。尽管观测到的动力学的丰富性,MCTDHB(M=3)的三个时间适应轨道能够描述系统的多玻色子量子动力学的短期和中期。然而,对于更长的时间,需要更多的自洽时间适应轨道来正确描述非平衡多体物理。证明了MCTDHB($M$)方法与所用的自洽含时轨道数$M$的收敛性。
英文摘要:
To solve the many-boson Schrödinger equation we utilize the Multiconfigurational time-dependent Hartree method for bosons (MCTDHB). To be able to attack larger systems and/or to propagate the solution for longer times, we implement a parallel version of the MCTDHB method thereby realizing the recently proposed [Streltsov {\it et al.} arXiv:0910.2577v1] novel idea how to construct efficiently the result of the action of the Hamiltonian on a bosonic state vector. We study the real-space dynamics of repulsive bosonic systems made of N=12, 51 and 3003 bosons in triple-well periodic potentials. The ground state of this system is three-fold fragmented. By suddenly strongly distorting the trap potential, the system performs complex many-body quantum dynamics. At long times it reveals a tendency to an oscillatory behavior around a threefold fragmented state. These oscillations are strongly suppressed and damped by quantum depletions. In spite of the richness of the observed dynamics, the three time-adaptive orbitals of MCTDHB(M=3) are capable to describe the many-boson quantum dynamics of the system for short and intermediate times. For longer times, however, more self-consistent time-adaptive orbitals are needed to correctly describe the non-equilibrium many-body physics. The convergence of the MCTDHB($M$) method with the number $M$ of self-consistent time-dependent orbitals used is demonstrated.