准二维空间中的隐秘涡旋量子液滴  

Hidden vortices of quantum droplets in quasi-two dimensional space

作　　者：陈逸熙 蔡晓妍 刘彬 江迅达 黎永耀[1,2] Chen Yi-Xi;Cai Xiao-Yan;Liu Bin;Jiang Xun-Da;Li Yong-Yao(School of Physics and Optoelectronic Engineering,Foshan University,Foshan 528225,China;Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology,School of Physics and Optoelectronic Engineering,Foshan University,Foshan 528225,China)

机构地区：[1]佛山科学技术学院物理与光电工程学院,佛山528225 [2]佛山科学技术学院,物理与光电工程学院粤港澳智能微纳光电技术联合实验室,佛山528225

出　　处：《物理学报》2022年第20期8-17,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11905032,11874112);广东省自然科学基金面上项目(批准号:2021A1515010214);广东省普通高校重点科研项目(批准号:2019KZDXM001);广东省基础与应用基础研究基金(批准号:2021A1515111015);粤港澳智能微纳光电技术联合实验室(批准号:2020B1212030010)资助的课题。

摘　　要：本文探究了弱囚禁条件下玻色-玻色混合凝聚体中的准二维隐秘涡旋量子液滴及其动力学特性.前期研究表明,在完全自由的三维空间中,隐秘涡旋量子液滴难以稳定;在二维系统中,当囚禁尺度是窄囚禁条件时,系统仅支持拓扑荷S_(1,2)=±1的隐秘涡旋量子液滴;因此当横向囚禁尺度较弱时,准二维空间中李-黄-杨修正项仍然采用三维空间中的表达式来描述,此时隐秘涡旋量子液滴能否保持稳定是一个重要的科学问题.本文采用虚时间方法获得了拓扑荷S_(1,2)达到±4的隐秘涡旋量子液滴;进一步论证了隐秘涡旋量子液滴的有效面积A_(eff)和化学势μ与总粒子数N之间的依赖关系;并采用线性稳定性分析结合实时传输方法获得了总粒子数临界值N_(th)分别与拓扑荷S_(1)和非线性系数δg之间的依赖关系.在动力学部分,本文研究了由两个不同拓扑荷的隐秘涡旋量子液滴构造的复合涡旋模式,即嵌套涡旋量子液滴.结合量子液滴的密度分布具有“平顶型”的特点,采用Thomas-Fermi近似对数值结果进行了有效验证.In this work,we study the quasi-two-dimensional hidden vortices of quantum droplets(QDs)trapped by a thicker transverse confinement and investigate their dynamical properties.Previous studies demonstrated that the hidden vortices of QDs in a three-dimensional free space are unstable and stable two-dimensional hidden vortices of QDs only with S_(1,2)=±1 can be supported by a thin transverse confinement.Under the conditions of thicker transverse confinement,the Lee-Huang-Yang correction term in quasi-two-dimensional space is still described in the form of the three-dimensional space.Hence,under this condition,the stability and characteristics of the hidden vortices of QDs are worth studying.By using the imaginary time method,the hidden vortices of QDs with topological charge S_(1,2) up to±4 are obtained for the first time.Furthermore,the dependence of the effective area A_(eff) and the chemical potentialμ on the total norm N_(th) of the hidden vortices of QDs are demonstrated.Besides,by using the linear stability analysis combined with the direct simulations,we obtain the dependence of the threshold norm Nth on the topological charge S_(1) and the nonlinear coefficient δg.Finally,we study the composite vortex pattern constructed by two hidden vortices of QDs,namely nested vortex QDs.Based on the fact that the hidden vortices of QDs generally have flat-top density profiles,the Thomas-Fermi approximation can be used to verify the numerical results effectively.The results of this paper can be extended in some directions,and provide a theoretical basis for the experimental realization of the hidden vortices of QDs.

关 键 词：玻色-爱因斯坦凝聚 GROSS-PITAEVSKII方程 隐秘涡旋 量子液滴 

分 类 号：O469[理学—凝聚态物理]