改进打靶法求解Gross-Pitaevskii方程及三个凝聚体的干涉

用改进的打靶法求解零温简谐势阱中中性原子玻色-爱因斯坦凝聚的一维Gross-Pitaevskii方程,给出不同非线性参数时凝聚体基态的本征值.用辛算法研究三个凝聚体在撤掉陷俘势后产生的干涉,和三个凝聚体处于同-陷俘势中的干涉及周期性演化,讨论不同的相对相位对凝聚体干涉的影响.     

磁偶极相互作用下玻色-爱因斯坦凝聚体中出现的奇特涡旋晶格结构

文章简要地介绍了玻色-爱因斯坦凝聚体中出现的涡旋和铬原子玻色-爱因斯坦凝聚体的实验研究进展，还介绍了文章作者的一项最新的理论工作。研究指出，由于铬原子磁偶极相互作用的影响，凝聚体中将出现奇特的各向异性的涡旋晶格结构。     

磁偶极相互作用下玻色-爱因斯坦凝聚体中出现的奇特涡旋晶格结构

文章简要地介绍了玻色-爱因斯坦凝聚体中出现的涡旋和铬原子玻色-爱因斯坦凝聚体的实验研究进展,还介绍了文章作者的一项最新的理论工作.研究指出,由于铬原子磁偶极相互作用的影响,凝聚体中将出现奇特的各向异性的涡旋晶格结构     

玻色-爱因斯坦凝聚体的相干寿命的光学操控及其应用

原子玻色-爱因斯坦凝聚体(BEC)所展现出的宏观量子相干性在非线性原子光学、集成原子光学,以及高精密原子测量仪器,比如原子干涉仪,原子陀螺仪,原子钟等方面有着潜在的应用.然而,当前实验室中所实现的玻色-爱因斯坦凝聚体由于存在环境及内禀消相干机制,如三体重组合碰撞等,其相干寿命仅仅在几秒到几分钟的范围.     

玻色子多体系统的平均场理论:玻色-爱因斯坦凝聚体(BEC)的冷却与激发

用量子主方程的平均场近似和代数动力学研究玻色-爱因斯坦凝聚体的sympathetic cooling; 用玻色-爱因斯坦凝聚体波函数的运动方程的平均场近似 非线性薛定谔方程研究玻色 爱因斯坦凝聚体的暗孤子和明孤子激发.     

虚光场对双模SU(1,1)相干态光场与原子玻色-爱因斯坦凝聚体相互作用系统中量子纠缠的影响

在双模SU(1,1)相干态光场和原子玻色-爱因斯坦凝聚体相互作用系统中, 应用全量子理论, 在非旋波近似下, 分别利用量子约化熵和量子相对熵, 研究了双模SU(1,1)相干态光场与原子玻色-爱因斯坦凝聚体间的量子纠缠和双模光场的模间纠缠, 讨论了虚光场、原子-场的耦合常数和光场参数对场-凝聚体原子纠缠和光场模间纠缠的影响.     

旋量玻色-爱因斯坦凝聚体拓扑性质的研究进展

实现玻色-爱因斯坦凝聚的原子大多具备内部自旋自由度,在光势阱下原子内部自旋被解冻,从而使原子可以凝聚到各个超精细量子态上,形成旋量玻色-爱因斯坦凝聚体.灵活的自旋自由度成为体系相关的动力学变量,可以使体系出现新奇的拓扑量子态,如自旋畴壁、涡旋、磁单极子、斯格明子等.本文综述了旋量玻色-爱因斯坦凝聚的实验和理论研究,旋量玻色-爱因斯坦凝聚体中拓扑缺陷的种类,以及两分量、三分量玻色-爱因斯坦凝聚体中拓扑缺陷的研究进展.     

原子间相互作用对原子激光压缩性质的影响

研究了原子间相互作用对光场与原子玻色-爱因斯坦凝聚体相互作用系统中耦合输出的相干原子束压缩性质的影响．结果表明：原子激光的两正交分量的涨落均可压缩，玻色-爱因斯坦凝聚体中原子间的相互作用不利于原子激光的压缩． 关键词： 玻色-爱因斯坦凝聚 压缩相干态光场 压缩原子激光     

V型三能级原子玻色-爱因斯坦凝聚体与双模压缩光场相互作用系统中光场的压缩特性

研究了V型三能级原子的玻色爱因斯坦凝聚体与双模压缩相干态光场相互作用系统中光场的压缩特性.结果表明:光场的两正交分量交替呈现周期性压缩现象,其压缩时间和压缩深度与光场的初始压缩因子密切相关 关键词： 玻色爱因斯坦凝聚体 V型三能级原子 双模压缩态光场 光场正交压缩     

原子玻色-爱因斯坦凝聚体对V型三能级原子激光压缩性质的影响

利用格子液体方法对V型三能级原子玻色-爱因斯坦凝聚体与双模压缩相干态光场相互作用系统的哈密顿量进行分析,发现文献中对原子间相互作用部分的处理有不合理之处,从而对该哈密顿量作出了改进并研究了V型三能级原子玻色-爱因斯坦凝聚体与双模压缩相干态光场相互作用系统中原子激光的两个正交分量的压缩性质.研究表明:V型三能级原子玻色-爱因斯坦凝聚体中光场-原子相互作用强度对原子激光的两正交分量的涨落有明显的影响. 关键词： 玻色-爱因斯坦凝聚 V型三能级原子 压缩相干态 压缩原子激光     

Rogue waves in nonlinear Schrödinger models with variable coefficients: Application to Bose–Einstein condensates

We explore the form of rogue wave solutions in a select set of case examples of nonlinear Schrödinger equations with variable coefficients. We focus on systems with constant dispersion, and present three different models that describe atomic Bose–Einstein condensates in different experimentally relevant settings. For these models, we identify exact rogue wave solutions. Our analytical findings are corroborated by direct numerical integration of the original equations, performed by two different schemes. Very good agreement between numerical results and analytical predictions for the emergence of the rogue waves is identified. Additionally, the nontrivial fate of small numerically induced perturbations to the exact rogue wave solutions is also discussed.     

Non-autonomous matter-wave solitons in hybrid atomic–molecular Bose–Einstein condensates with tunable interactions and harmonic potential

In this paper, we investigate matter-wave solitons in hybrid atomic–molecular Bose–Einstein condensates with tunable interactions and external potentials. Three types of time-modulated harmonic potentials are considered and, for each of them, two groups of exact non-autonomous matter-wave soliton solutions of the coupled Gross–Pitaevskii equation are presented. Novel nonlinear structures of these non-autonomous matter-wave solitons are analyzed by displaying their density distributions. It is shown that the time-modulated nonlinearities and external potentials can support exact non-autonomous atomic–molecular matter-wave solitons.     

Formation of parametric solitons in coupled atom–molecule quantum gases via controlled nonlinear interactions

We consider an atomic Bose–Einstein condensate parametrically coupled to a molecular condensate with tunable interactions. The space distribution and nonlinear dynamics of this coupled system, especially the parametric solitons, are investigated within the full parameter space accounts for all the nonlinear two-body collisions, together with the atom–molecule conversion coupling and the bare formation energy of the molecular species. The results show that the exact parametric solitons can be formed via controlled nonlinear interactions, and the atom–molecule transfer term can provide an effective potential which can be used to stable the coupled system even in the absence of the external potential. We also give an experimental setup and detection of the atomic–molecular Bose–Einstein condensates in future experiments.     

Coherent manipulation and guiding of Bose–Einstein condensates by optical dipole potentials

The coherent manipulation of Bose–Einstein condensates by far blue detuned optical dipole potentials is discussed in two regimes. The local manipulation of the phase of the condensate wavefunction by temporally applied dipole potentials represents a powerful tool for the design of matter waves. We use this method in particular for the creation of dark solitons in Bose–Einstein condensates and study their dynamics. Spatially inhomogeneous dipole potentials like far blue detuned doughnut laser beams can be used for the creation of Bose–Einstein condensates within a waveguide structure.     

Ground state properties of a Bose－Einstein condensate confined in an anharmonic external potential

In light of the interference experiment of Bose－Einstein condensates, we present an anharmonic external potential model to study ground state properties of Bose－Einstein condensates. The ground state energy and the chemical potential have been analytically obtained, which are lower than those in harmonic trap. Additionally, it is found that the anharmonic strength of the external potential has an important effect on density and velocity distributions of the ground state for the Thomas－Fermi model.     

Elliptic Function Waves of Spinor Bose-Einstein Condensates in an Optical Lattice

An improved nonlinear Schrodinger equation different from usual one of spinor Bose-Einstein condensates （BECs） in an optical lattice are obtained by taking into account a nonlinear term in the equation of motion for probability amplitude of spins carefully. The elliptic function wave solutions of the model are found under specific boundary condition, for example, the two ends of the atomic chain are fixed. In the case of limit the elliptic function wave solutions are reduced into spin-wave-like or solitons.     

Matter wave interference of dilute Bose gases in the critical regime

Ultra-cold atomic gases provide a new chance to study the universal critical behavior of phase transition. We study theoretically the matter wave interference for ultra-cold Bose gases in the critical regime. We demonstrate that the interference in the momentum distribution can be used to extract the correlation in the Bose gas. A simple relation between the interference visibility and the correlation length is found and used to interpret the pioneering experiment about the critical behavior of dilute Bose gases [Science 315 1556(2007)]. Our theory paves the way to experimentally study various types of ultra-cold atomic gases with the means of matter wave interference.     

The physics of trapped dilute-gas Bose–Einstein condensates

The experimental realisation of Bose–Einstein condensates of dilute atomic vapours has generated immense interest and activity in this field. Here, we present a review of recent theoretical research into the properties of trapped dilute-gas Bose–Einstein condensates. Topics covered include ground-state properties of trapped condensates, elementary excitations, light scattering properties, tests of broken gauge symmetry, and the atom laser.     

Wave functions,relative phase and interference for atomic Bose–Einstein condensates

In this article, we present a tutorial discussion of the coherence properties of Bose–Einstein condensates. We use a formalism which is similar to the one used in quantum optics. We describe within the variational approximation the question of the relative phase of two condensates. To evaluate the structure factors of a condensate, we briefly review the Bogolubov approach and describe light scattering off a condensate using the linear response formalism. Finally, we study the effect of atomic interactions on the condensate's dynamics.