奇偶相干态的高阶压缩及其准概率分布函数

本文研究了奇偶相干态的高阶压缩和它们的各种准概率分布函数,结果表明,这两个态的高阶压缩性质是相互排斥的,特征函数和Wigner函数都不是高斯型,而且Wigner函数也不恒为正定,准概率密度(QPD)图形既不是椭圆,也不是月牙状,而是两叶花瓣状,显示出态的QPD图形不能说明态的压缩类型。 关键词：     

双模激发压缩真空态的维格纳函数

利用纠缠态表象下的维格纳(Wigner)算符,构造了双模激发压缩真空态的维格纳函数,并根据该函数在相空间ρ-γ中随参量m,n和r的变化关系,讨论了双模激发压缩真空态的量子干涉特性和压缩效应。结果表明,对于参量m,n不同的取值,双模激发压缩真空态的量子干涉效应的强弱不同;而对于不同的压缩参量r,双模激发压缩真空态呈现出不同程度的压缩效应。最后,根据双模激发压缩真空态的维格纳函数的边缘分布,阐明了此维格纳函数的物理意义。     

热真空态的Husimi分布函数

根据量子统计中相空间的理论知识,采用两种不同的方法给出了热真空态的Husimi分布函数,并给出了热真空态的Wehrl墒.最后与相应混合态的Husimi分布函数进行比较,得出来热真空态的Husimi分布函数与混合态的Husimi分布函数是相一致的结论.     

双模压缩真空态和纠缠相干态的一维势垒散射

分析了双模压缩真空态和纠缠相干态的一维势垒散射问题,结果表明,两种散射态的纠缠度都随势垒的透射系数呈类抛物线关系,且抛物线谷底对应半反半透势垒.前者的纠缠度还随入射压缩因子呈类抛物线关系,后者随入射纠缠呈线性关系.两种散射的保真度都可以由透射系数的增加而得到提高,但前者还会随入射压缩因子的增大而降低,后者随入射相干态模的增加而降低.     

电子的衍射态及其几率分布

本文用路径积分概念导出了电子经单缝、双缝及多缝衍射后的量子态及其几率分布，证明了电子经缝的衍射结果与光子的衍射结果一致．     

结合双模压缩真空态对EPR“佯谬”与量子力学几率波的统一性解释

文章分析了爱因斯坦等人对量子力学不完备的论证过程，通过对双模压缩真空态的偏振正交两光束EPR关联实质讨论，结合EPR光束对实验产生，给出了量子力学几率波解释与EPR“佯谬”的统一必解释，从而在肯定EPR关联实在性的基础上，肯定了量子力学几率波解释的完备性。     

任意两个相干态的叠加态的相位分布和Wigner函数

从相位分布和Wigner函数两个方面研究了任意两个相干态|β〉 and |mβeiδ〉的叠加态的量子统计性质.结果表明这种叠加态的非经典特性与β2,振幅系数m,相干态间的位相差δ以及叠加系数间的位相差都有关.当参量选择合适,这种叠加态存在着量子效应.计算了两个相干态等几率混合系综的相位分布和Wigner函数,经过与前者比较,结果表明由于相干项的存在,使得叠加态具有很好的量子力学行为.     

量子相空间分布函数与压缩相干态表示间的变换关系

基于Husimi算符具有压缩相干态投影子形式, 首先介绍了一个新的量子算符表示, 即压缩相干态表示.当高斯展宽参数κ = 1时, 该函数约化为通常的P函数. 作为例子, 研究了热态的压缩相干态表示, 通过图示说明了压缩相干态表示与P函数的区别. 为更好地在量子光学问题中使用该表示, 我们揭示了压缩相干态表示与Wigner函数、Q函数以及Husimi函数间的积分变换关系.     

Husimi算符与热真空态的Husimi分布函数

利用Husimi算符作为一个纯态密度算符的事实,我们导出了热场态的Husimi函数及其边缘分布.通过绘制相空间的Husimi分布图形,我们简要讨论了高斯展宽参数以及热真空态的温度对Husimi函数的影响.     

用纠缠态表象讨论对双模压缩真空态作正交振幅分量的测量

对文献[4]的结果作了进一步推导,用纠缠态表象方法计算了对双模压缩真空态第一个模场作正交振幅分量测量的结果,发现第二个模塌缩到一个压缩态,其显式被导出。     

Some Properties of Two-mode Displaced Excited Squeezed Vacuum States

In this paper, two-mode displaced excited squeezed vacuum states （TDESVS） are constructed and their normalization and completeness are investigated. Using the entangled state representation and Weyl ordering form of the Wigner operator, the Wigner functions of TDESVS are obtained and the variations of Wigner functions with the parameters m, n and r are investigated. Besides, two marginal distributions of Wigner functions of TDESVS are obtained, which exhibit some entangled properties of the two-particle＇s system in TDESVS.     

叠加压缩相干态的量子统计性质

研究了叠加压缩相干态的量子统计性质,给出了压缩和反聚束效应与叠加系数之间的关系。结果表明,叠加压缩相干态具有压缩和反聚束的现象。压缩奇偶相干态的有关结果均作为特例包含在本文的一般结论之中。     

Photon-Added Entangled Coherent State

We propose a feasible scheme to create the single-mode or two-mode photon-added entangled coherent state (PAECS) and then compare its entanglement degree with that of the entangled coherent state or even the photon-added-and-subtracted entangled coherent state.     

Properties of Coherent State for Hydrogen Atom

We construct the coherent state for the two-dimensional hydrogen atom, for which the averaged motion ofposition describes a Kepler ellipse. The coherent state can be expanded with respect to the eigenstates of 2D hydrogenatom, from which we evaluate the binding energy of the wave packet for this state.     

Two-Mode Excited Squeezed Vacuum State and Its Properties

In this paper, the two-mode excited squeezed vacuum state (TESVS) is studied by using the statistical method. By calculating the normalization of the TESVS, a new form of Jacobi polynomials and some new identities are obtained. The photon number distribution of the TESVS is given and it is a simple form of Jacobi polynomials. Using the entangled state representation of Wigner operator, the Wigner function of the TESVS is obtainded and the variations of the Wigner function with the parameters m, n, and r are discussed. Here from the phase space point of view the TESVS can be well interpreted and described.     

Effect of Coherent State of Quarks and Mesons on Hadron Properties

The effect of coherent state of quarks and mesons on hadron properties has been investigated in a chiral quark model. A new parameter set is derived. A comparison with previous work shows that the properties of the nucleon and delta are greatly improved by increasing the degree of coherent and the sigma-meson mass.     

Generation of Four-Photon Coherent State via Degenerate Raman Interaction

A scheme is presented for generating a four-photon coherent state via the degenerate Raman interaction. The scheme does not need classical fields to manipulate the atoms. Its another advantage is that the atomic spontaneous emission can be neglected. Therefore, the coherence of the system may be better maintained. The scheme can be generalized to generate superposition of 2ⁿ coherent states and superposition of 2ⁿ two-mode coherent states. The coherent states in each mode are on a circle symmetrically.     

振幅衰减模型中弱相干光场的退相干

利用热纠缠态表象求解密度矩阵主方程的方法,给出了任意时刻振幅衰减模型中弱相干场密度算符的表示式。采用数值计算方法计算了弱相干光场的压缩效应、统计性质和Wigner函数。讨论了耗散对这些量子特性的影响。研究结果表明:随衰减时间的增大,弱相干场的压缩效应、统计性质和Wigner函数的负性等非经典效应均减弱。