两维有限深势阱中BEC的稳定性分析  

The Stability of BEC in a Two-dimensional Finite Potential Well

作　　者：简粤 祁鹏堂 李伟 张培增 郑小平 JIAN Yue;QI Pengtang;LI Wei;ZHANG Peizeng;ZHEN Xiaopin(Department of Basic courses, Lanzhou Institute of Technology, Lanzhou 730050;College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070;Lanzhou City University , Lanzhou, 730000, China)

机构地区：[1]兰州工业学院基础学科部,甘肃兰州730050 [2]西北师范大学物理与电子工程学院,甘肃兰州730070 [3]兰州城市学院,甘肃兰州730000

出　　处：《低温物理学报》2019年第3期164-170,共7页Low Temperature Physical Letters

基　　金：甘肃省自然科学基金(批准号:18JR3RA230,223,217);甘肃省高等学校科研项目(批准号:2018D-19);兰州市人才创新创业项目(批准号:114);甘肃省2019年度重点人才项目;兰州工业学院“开物”科研创新团队支持计划资助(编号:2018KW-06);兰州工业学院青年科技创新项目(编号:17K-018)资助的课题

摘　　要：研究两维轴对称有限深势阱中BEC的稳定性,利用变分法分别讨论了系统的基态和激发态特性。研究表明系统存在塌缩态、束缚态和扩散态三种状态,并计算出系统状态发生变化的耦合常数的两个临界值,发现势阱的形状与系统的稳定性紧密相关。同时在激发态下进一步讨论了原子间相互作用发生周期性调制的BEC的动力学特性,分析发现有限深势阱中BEC的塌缩可以通过周期性调制散射长度来控制。本文最后讨论了涡旋态下BEC的稳定性,发现系统的塌缩点由于涡旋态的存在而降低。The stability of BEC in a two-dimensional axisymmetric finite deep well is studied. The ground state and excited state of the system are discussed by using variational method. The results show that there are three states of collapse state, bound state and diffusion state, and the two critical values of coupling constant of the system state change are calculated. The state of the system is closely related to the shape of the potential well. At the same time, the dynamic characteristics of BEC which is periodically modulated by the interaction between atoms are further discussed in the excited state. It is found that the collapse of BEC in a finite deep well can be controlled by modulating the scattering length periodically. Finally, the stability of BEC in the vortex state is discussed. Because of the existence of the vortex state, the collapse point of the system decreases.

关 键 词：玻色-爱因斯坦凝聚 有限深势阱 耦合常数塌缩 束缚态 扩散态 

分 类 号：O469[理学—凝聚态物理]