Stability and dynamics of vortex clusters in nonrotated Bose-Einstein condensates
Stability and dynamics of vortex clusters in nonrotated Bose-Einstein condensates
复制标题
DOI：
10.1103/physreva.74.023603
复制
发表时间：
2006-08
影响因子：
2.9
通讯作者：
V. Pietilä;M. Möttönen;T. Isoshima;J. Huhtamäki;S. Virtanen
中科院分区：
文献类型：
--
作者：
V. Pietilä;M. Möttönen;T. Isoshima;J. Huhtamäki;S. Virtanen
我们研究了限制在非旋转谐波陷阱中的薄煎饼状玻色-爱因斯坦凝聚体中的涡旋和反涡团。先前关于这些拓扑非平凡激发态的稳定性的理论结果似乎是矛盾的。我们通过系统的稳定性分析来澄清这种情况。通过求解Bogoliubov方程得到相应的元激发光谱，确定了团簇的能量和动力学稳定性。此外，我们还研究了动态不稳定团簇的时间演化。团簇的稳定性及其失稳模式的特征仅取决于粒子间相互作用的有效强度和陷阱的各向异性。对于这些参数的某些值，存在几个动力学不稳定性，但我们表明，也有一些集群的动态稳定的区域。此外，我们观察到，集群的动力学不稳定性并不总是意味着它们的结构不稳定性，并且对于一些动力学不稳定的状态，涡旋的湮灭之后是它们的再生，以及集群的复兴。
We study stationary clusters of vortices and antivortices in dilute pancake-shaped Bose-Einstein condensates confined in nonrotating harmonic traps. Previous theoretical results on the stability properties of these topologically nontrivial excited states are seemingly contradicting. We clarify this situation by a systematic stability analysis. The energetic and dynamic stability of the clusters is determined from the corresponding elementary excitation spectra obtained by solving the Bogoliubov equations. Furthermore, we study the temporal evolution of the dynamically unstable clusters. The stability of the clusters and the characteristics of their destabilizing modes only depend on the effective strength of the interactions between particles and the trap anisotropy. For certain values of these parameters, there exist several dynamical instabilities, but we show that there are also regions in which some of the clusters are dynamically stable. Moreover, we observe that the dynamical instability of the clusters does not always imply their structural instability, and that for some dynamically unstable states annihilation of the vortices is followed by their regeneration, and revival of the cluster.