Dynamically stable multiply quantized vortices in dilute Bose-Einstein condensates
Dynamically stable multiply quantized vortices in dilute Bose-Einstein condensates
复制标题
稀玻色-爱因斯坦凝聚体中的动态稳定多重量子化涡旋
DOI：
10.1103/physreva.74.063619
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
S. Virtanen
中科院分区：
文献类型：
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作者：
J. Huhtamaki;M. Mottonen;S. Virtanen
被限制在雪茄形长阱中的稀原子玻色-爱因斯坦凝聚体中的多量子涡旋在能量和动力学上都是不稳定的。即使在超低温极限下，它们也倾向于分裂成单量子涡旋，耗散非常弱，这在最近的实验中也得到了证实[Y。Shin等人，物理修订信函93，160406（2004）]利用所谓的拓扑相位工程方法来创建多量子涡旋。通过求解多量子涡旋态的Bogoliubov激发谱，研究了多量子涡旋在不同阱几何中的稳定性。我们发现，在陷阱不对称性和凝聚相互作用强度平面中，存在多量子涡旋的分裂不稳定性被抑制的区域，因此它们是动力学稳定的。例如，双量子化涡旋可以动态稳定，即使在很宽的相互作用强度值范围内的球形陷阱。我们希望这种抑制涡分裂不稳定性可以得到实验验证。
Multiquantum vortices in dilute atomic Bose-Einstein condensates confined in long cigar-shaped traps are known to be both energetically and dynamically unstable. They tend to split into single-quantum vortices even in the ultralow temperature limit with vanishingly weak dissipation, which has also been confirmed in the recent experiments [Y. Shin et al., Phys. Rev. Lett. 93, 160406 (2004)] utilizing the so-called topological phase engineering method to create multiquantum vortices. We study the stability properties of multiquantum vortices in different trap geometries by solving the Bogoliubov excitation spectra for such states. We find that there are regions in the trap asymmetry and condensate interaction strength plane in which the splitting instability of multiquantum vortices is suppressed, and hence they are dynamically stable. For example, the doubly quantized vortex can be made dynamically stable even in spherical traps within a wide range of interaction strength values. We expect that this suppression of vortex-splitting instability can be experimentally verified.