偶极-偶极相互作用下玻色-爱因斯坦凝聚体中涡旋的非线性动力学研究

Nonlinear dynamics of vorices in a bose-Einstein condendsate with dipole-dipole interaction

基于平均场理论和分裂算符谱算法,研究了偶极-偶极相互作用下玻色爱因斯坦凝聚体中涡旋的非线性动力学.研究发现外势运动速度小于临界值时,偶极-偶极相互作用对系统涡旋的非线性动力学影响较小,而外势运动速度超过临界速度时,偶极-偶极相互作用对涡旋的非线性动力学影响很大,可使系统产生涡旋对、涡旋偶极子和简单涡旋,并使它们形成涡街.

Based on the mean - field theory and split - operator method, we study the nonlinear dynamics of vor- tices in a Bose- Einstein condensate with dipole -dipole interaction. The results show that the dipole -dipole interaction has little effect on the nonlinear dynamics of vortices when the speed of the impenetrable disk - shaped potential is smaller than a critical value of speed, however, when the speed of the impenetrable disk - shaped potential exceeds the critical value of speed, the dipole - dipole interaction will affect the nonlinear dynamics of vortices strongly. Vortex pairs, vortex dipoles and vortices are formed in such a system within a certain range of parameters. Moreover, they formed vortex streets.