物理学报2024，Vol.73Issue(11)：1-9,9.DOI:10.7498/aps.73.20232003
双组分玻色-爱因斯坦凝聚体中PT对称势下的异步量子Kármán涡街
Asynchronous quantum Kármán vortex street in two-component Bose-Einstein condensate with PT symmetric potential
摘要
Abstract
The dynamics of a miscible two-component Bose-Einstein condensate(BEC)with PT(parity-time)symmetric potential are investigated numerically.The dynamical behaviors of the system is described by Gross-Pitaevskii(GP)equations under the mean-field theory.Firstly,the ground state of the system is obtained by the imaginary-time propagation method.Then dynamical behaviors are numerically simulated by the time-splitting Fourier pseudo-spectral approach under periodic boundary conditions.By adjusting the width and velocity of the obstacle potential,various patterns such as no vortex,oblique drifting vortex dipole,V-shaped vortex pairs,irregular quantum turbulence and combined modes are studied.It is noted that the shedding vortex pairs in components 1 and 2 are staggered,which is called"the asynchronous quantum Kármán vortex street".Here,the ratio of the distance between two vortex pairs in one row to the distance between vortex rows is approximately 0.18,which is less than the stability criterion 0.28 of classical fluid.We calculated the drag force acting on the obstacle potential during generation of the asynchronous quantum Kármán vortex street.It is found that periodical oscillation of the drag force is generated via drifting up or down of the vortex pairs.Meanwhile,we analyzed the influence of the imaginary part of the PT symmetric potential with gain-loss for wake.The trajectory and frequency of the vortex are changed,due to the imaginary part breaks the local symmetry of the system.In addition,the imaginary part affects the stability of the asynchronous quantum Kármán vortex street.Lots of numerical simulations are carried out to determine the parameter regions of various vortex shedding modes.We also proposed an experimental protocol to realize the asynchronous quantum Kármán vortex street in the miscible two-component BEC with PT symmetric potential.关键词
玻色-爱因斯坦凝聚体/Kármán涡街/PT对称势Key words
Bose-Einstein condensate/Kármán vortex street/PT symmetric potential引用本文复制引用
邵凯花,席忠红,席保龙,涂朴,王青青,马金萍,赵茜,石玉仁..双组分玻色-爱因斯坦凝聚体中PT对称势下的异步量子Kármán涡街[J].物理学报,2024,73(11):1-9,9.基金项目
国家自然科学基金(批准号:12065022,12147213)资助的课题. Project supported by the National Natural Science Foundation of China(Grant Nos.12065022,12147213). （批准号:12065022,12147213）
