球对称非谐势阱中玻色-爱因斯坦凝聚Gross-Pitaevskii方程的精确解

考虑了描述玻色 爱因斯坦凝聚的Gross-Pitaevskii(GP)方程, 得到了在球对称非谐势阱中玻色-爱因斯坦凝聚GP方程的精确亮孤子解。In this paper, we analyze Gross Pitaevskii equation which describes the dynamics of a bright soliton in trapped atomic Bose Einstein condensates, and obtain the exact bright soliton solution of Gross Pitaevskii equation in spherically symmetric non harmonic trap.     

简谐势阱中具有吸引相互作用原子体系的玻色-爱因斯坦凝聚

给出了简谐势阱中具有吸引相互作用原子体系的非线性定态薛定谔方程的基态解,得到了凝 聚原子数随能量本征值变化的双稳态曲线.并由此得到与实验报道相符的吸引型玻色-爱因斯 坦凝聚体所能包含的最大原子数. 关键词： 玻色-爱因斯坦凝聚 双稳态     

非谐势阱中玻色-爱因斯坦凝聚的数值计算

从G-P平均势场理论出发,探讨了玻色-爱因斯坦凝聚(BEC)的G-P方程的一维形式,用数值计算方法研究了非谐势阱中非理想玻色凝聚气体的基态和第一激发态解.给出了能量随非线性系数的变化规律.     

玻色-爱因斯坦凝聚实现10周年

自1995年首次实现玻色一爱因斯坦凝聚（BEC）以来，相关研究发展迅速．截止到2005年6月，已实现凝聚的碱金属原子气有六种：7^Li，23^Na，41^K,85^Rb，和133^Cs．自旋极化1^H最早被遴选为BEC的对象，但因技术上的难度问题，它的凝聚迟至1998年6月，是由“BEC教父”Daniel Kleppneer领导的小组实现的．     

外势场作用下的玻色-爱因斯坦凝聚啁啾孤子的演化与操控

提出了一种处理玻色-爱因斯坦凝聚啁啾孤子动力学的拓展变分方法,深入研究了玻色-爱因斯坦凝聚孤子在周期势与抛物势联合作用下的动力学演化,利用拓展变分法给出了解析处理,并和基于分步傅里叶变换的直接数值法进行比较,发现这种拓展变分方法能够充分揭示上述外势场中的玻色-爱因斯坦凝聚啁啾孤子的动力学行为和特征．同时给出了能支持多稳定晶格囚禁玻色-爱因斯坦凝聚啁啾孤子的周期势与抛物势强度比值的临界值和一种通过控制外势场可有选择地移动玻色-爱因斯坦凝聚啁啾孤子的操控方法,这为玻色-爱因斯坦凝聚的实验和应用研究提供了理论参 关键词： 玻色-爱因斯坦凝聚 Gross-Pitaevskii方程 啁啾孤子 操控     

排斥势中随时间变化原子间相互作用的玻色-爱因斯坦凝聚的亮孤子的动力学

简要地介绍了玻色-爱因斯坦凝聚现象及国际学术界的实验研究动态和最近的一项理论研究进展.给出了一个一维非线性薛定谔方程的严格解,它描述了在一个排斥势中随时间变化的原子间相互作用的玻色-爱因斯坦凝聚的一个亮孤子的动力学.     

谐振子势阱囚禁玻色气体的玻色-爱因斯坦凝聚

基于Thomas-Fermi半经典近似方法研究了谐振子势阱约束下任意维理想玻色气体的玻色-爱因斯坦凝聚(BEC)．导出了玻色气体的BEC转变温度、基态粒子占据比例、内能和热容量等物理量的解析表达式,讨论了空间维度和谐振子势阱的影响．以二维和三维玻色系统为例,数值计算了上述热力学量,并与解析结果进行了对比,二者获得了较好的吻合．     

谐振子势阱囚禁玻色气体的玻色-爱因斯坦凝聚

基于Thomas-Fermi半经典近似研究了谐振子势阱约束下任意维理想玻色气体的玻色-爱因斯坦凝聚(BEC).导出了玻色气体的BEC转变温度、基态粒子占据比例、内能和热容量等物理量的解析表达式,讨论了空间维度和谐振子势阱的影响.以二维和三维玻色系统为例,数值计算了上述热力学量,并与解析结果进行了对比,二者获得了较好的吻合.     

物理学家产生新的物态：玻色—爱因斯坦凝聚

１９９５年６月５日．美国国家标准和技术研究所和科罗拉多大学物理系联合研究所（ＪＩＬＡ）的物理学家怀曼（Ｃ．ｗｉｅｍａｎ）和康耐尔（Ｅ．Ｃｏｒｎｅｌｌ）等人，采用激光冷却和蒸发冷却的联合技术．首先在原于钩（８７Ｒｂ）的蒸汽中产生了玻色－爱因斯坦凝聚（ＢＥＣ），使上千个原子进入同一个量子态［１］．这一发现轰动了整个物理界，美国《科学》杂志显要地报道了这个消息［２，３］．麻省理工学院的一位在探素ＢＥＣ方面很有经验的原子物理学家——克理普耐尔（Ｋｌｅｐｐｎｅｒ）说：“这是一项惊人的发现，简直让我透不过气…     

三势阱中玻色-爱因斯坦凝聚的开关特性

应用平均场近似的方法,研究了弱耦合的三势阱中玻色-爱因斯坦凝聚的开关效应.当粒子置于左阱时,可以通过在中间势阱中加入少量粒子控制左阱粒子向右阱的隧穿,从而呈现出明显的导通与截止行为.对中间势阱的深度和相对相位的影响也进行了讨论,并指出了该理论模型的一些潜在应用前景. 关键词： 玻色-爱因斯坦凝聚 开关效应 三势阱 平均场近似     

具有三体作用的玻色-爱因斯坦凝聚暗孤子的演化

运用变分法研究了具有三体作用的玻色-爱因斯坦凝聚暗孤子的演化特性,分析了调谐囚禁电势对暗孤子运动的影响.结果表明,囚禁在调谐势阱中的暗孤子将振动,势阱强度和三体作用的符号影响了暗孤子的演化,并改变了BEC系统的振动特性.     

Soliton Solutions in Three-Component Bose-Einstein Condensates

We obtain soliton and plane wave solutions for the coupled nonlinear Schrotinger equations, which describe the dynamics of the three-component Bose-Einstein condensates by using the Hirota method. Meanwhile we find that the system which has attractive atomic interaction will only possess a shape changing （inelastic） collision property due to intensity redistribution in the absence of the spin-exchange interaction. As a discussed example, we investigate the one-soliton, two-soliton solutions and collisional effects between bright two-soliotn solution, which lead to the intensity redistribu tion.     

Soliton breathers in spin-1 Bose–Einstein condensates

We consider a spin-1 Bose-Einstein condensate trapped in a harmonic potential with different nonlinearity coeffi- cients. We illustrate the dynamics of soliton breathers in two-component and three-component states by numerically solv- ing the one-dimensional time-dependent coupled Gross-Pitaecskii equations （GPEs）. We present that two condensates with repulsive interspecies interactions make elastic collision and novel soliton breathers are created in two-component state. We also demonstrate novel soliton breathers in three-component state with attractive coupling constants. Furthermore, possible reasons for creating soliton breathers are discussed.     

Phase of Bose-Einstein Condensate Interacting with a Time-Dependent Laser Field

By using of the invariant theory, we have studied phase of Bose-Einstein condensate in a double-well potential interacting with a time-dependent single-mode traveling-wave laser field, the dynamical and geometric phases are presented respectively. The Aharonov-Anandan phase is also obtained under the cyclical evolution. PACS number: 03.65.Vf; 03.75.Mn.     

Phase of a Bose-Einstein Condensate in a Double-Well Potential Modulated Periodically in Time

By using of the invariant theory, we have studied phase of a Bose-Einstein condensate in a double-well potential modulated periodically in time when the on-site interaction energy of a single pair of bosons occupying the same well equals the collision energy between two condensates, the dynamical and geometric phases are presented respectively. The Aharonov-Anandan phase is also obtained in the case of the cyclical evolution. PACS:03.65.Vf; 03.75.Mn     

New Families of Soliton and Periodic Solutions of Bose-Einstein Condensation in Linear Magnetic Field and Time-Dependent Laser Field

By using a new generally projective Riccati equation method and with the help of symbolic computation,we consider a nonlinear Gross-Pitaevskii equation with weak bias magnetic and time-dependent laser fields. As a result,some new soliton solutions, rational function solution, and periodic solutions are obtained.     

Analyzing Dynamics of a Bright Soliton in Bose-Einstein Condensates with Time-Dependent Atomic Scattering Length

We analyze the dynamics of a bright soliton in atomic scattering length in an expulsive parabolic potential. Bose-Einstein condensates （BECs） with time-dependent Under a safe ravage of parameters in which the Gross-Pitaevskii （GP） equation is effective in one dimension, our results show that, the dynamics of the bright soliton can be classed into two phases, depending on the value of the scattering length. Meanwhile, there exists a critical value of the absolute value of the atomic scattering length, below which, the dynamics of the bright soliton is very regular. Those phenomena can be useful for developing concrete applications of the nonlinear matter waves. We also obtain the orbital equation of the bright soliton and get some interesting data which may be useful for the experimental observation of the bright soliton and the application of the atom laser with manipulated intensity.     

Analyzing Dynamics of a Bright Soliton in Bose-Einstein Condensates with Time-Dependent Atomic Scattering Length

We analyze the dynamics of a bright soliton in Bose-Einstein condensates (BECs) with time-dependent atomic scattering length in an expulsive parabolic potential. Under a safe range of parameters in which the Gross-Pitaevskii (GP) equation is effective in one dimension, our results show that, the dynamics of the bright soliton can be classed into two phases, depending on the value of the scattering length. Meanwhile, there exists a critical value of the absolute value of the atomicscattering length, below which, the dynamics of the bright soliton is very regular. Those phenomena can be useful for developing concrete applications of the nonlinear matter waves. We also obtain the orbital equation of the bright soliton and get some interesting data which may be useful for the experimental observation of the bright soliton and the application of the atom laser with manipulated intensity.