Boudjemâa Abdelâali, Guebli Nadia, Sekmane Mohammed, Khlifa-Karfa Sofyan
Department of Physics, Faculty of Exact Sciences and Informatics, Hassiba Benbouali University of Chlef, P.O. Box 78, 02000, Ouled Fares, Chlef, Algeria.
J Phys Condens Matter. 2020 Jul 16;32(41). doi: 10.1088/1361-648X/ab997a.
We consider impurity atoms embedded in a two-component Bose-Einstein condensate in a quasi-one dimensional regime. We study the effects of repulsive coupling between the impurities and Bose species on the equilibrium of the system for both miscible and immiscible mixtures by numerically solving the underlying coupled Gross-Pitaevskii equations. Our results reveal that the presence of impurities may lead to a miscible-immiscible phase transition due to the interaction of the impurities and the two condensates. Within the realm of the Bogoliubov-de Gennes equations we calculate the quantum fluctuations due to the different types of interactions. The breathing modes and the time evolution of harmonically trapped impurities in both homogeneous and inhomogeneous binary condensates are deeply discussed in the miscible case using variational and numerical means. We show in particular that the self-trapping, the miscibility and the inhomogeneity of the trapped Bose mixture may strongly modify the low-lying excitations and the dynamical properties of impurities. The presence of phonons in the homogeneous Bose mixture gives rise to the damping of breathing oscillations of impurities width.
我们考虑准一维体系中嵌入两组分玻色 - 爱因斯坦凝聚体中的杂质原子。通过数值求解基础的耦合格罗斯 - 皮塔耶夫斯基方程，我们研究了杂质与玻色子种类之间的排斥耦合对可混溶和不可混溶混合物体系平衡的影响。我们的结果表明，由于杂质与两种凝聚体的相互作用，杂质的存在可能导致可混溶 - 不可混溶相变。在博戈留波夫 - 德热纳方程的框架内，我们计算了由于不同类型相互作用引起的量子涨落。在可混溶情况下，使用变分法和数值方法深入讨论了均匀和非均匀二元凝聚体中杂质的呼吸模式以及谐波捕获杂质的时间演化。我们特别表明，捕获的玻色混合物的自捕获、可混溶性和不均匀性可能会强烈改变杂质的低能激发和动力学性质。均匀玻色混合物中声子的存在导致杂质宽度呼吸振荡的阻尼。
