基于双模相干-纠缠态表象的算符恒等式构造法

利用最近引进的相干-纠缠态|x,α〉表象和有序算符内的积分技术,给出了关于双模光场正交分量（X₁+X₂）/2^1/2和参数化的正交分量（μX₁+νX₂）/λ的函数的若干正规乘积展开式,这对于研究场的高阶压缩行为和构建广义压缩态是有用的. 关键词： 双模相干-纠缠态 算符恒等式 有序算符内的积分技术     

基于纠缠态表象的复脊波变换理论

本文基于连续变量量子态构造小波变换的研究结果, 从经典信息的连续脊波变换出发, 利用有序算符内ket-bra型积分, 构造连续复脊波变换对应的量子算符和表象表示, 采用表象的内积运算与态矢投影展开, 研究量子光学态的复脊波变换理论. 关键词： 有序算符内积分技术 复脊波变换 纠缠态表象 相干态     

由光分束器和起偏器混合产生的三模纠缠态表象

在三模Fock空间中,本文构建了一种新的三模连续变量纠缠态,它构成了一个新的量子力学表象.该态可以利用非对称光束分离器和起偏器实现.态的纠缠性通过获得其相应的施密特分解得以说明.作为该表象的一个重要应用,利用它实现了单粒子态的量子隐态传输,给出了相应的传输方案. 关键词： 三模连续纠缠态表象 有序算符内的积分技术 量子纠缠 量子隐态传输     

研究热相干态的Wigner函数

利用相干态表象下的Wigner算符和有序算符内的积分(IWOP)技术,首先得到了热相干态(量子纯态)的Wigner函数;同时借助相干态表象和算符的正规乘积形式给出了相应混合态的Wigner函数.结果表明,热相干态与相应混合态的Wigner甬数是相一致的,支持了热场动力学(TFD)理论.且采用相干态表象下的Wigner算符、IWOP技术和算符的正规乘积形式来研究量子态的Wigner函数非常简捷方便.研究结果加深了人们对量子统计中相空间技术和热场动力学(TFD)理论的认识,且对于其它量子纯态与相应混合态相空间分布函数一致性的研究具有很好的理论指导意义.     

Schwinger Bose实现下自旋相干态Wigner函数的特性分析

在Schwinger Bose实现下,引入纠缠态表象及Wigner算符在该表象下的表示,得到自旋相干态的Wigner函数,数值计算画出相空间中Wigner函数的分布图,并加以分析,发现在SchwingerBose实现下自旋相干态确实体现出纠缠特性。     

利用热纠缠态表象获得Caldeira-Leggett密度算符方程的积分形式解

开放量子系统,即系统-热库模型,可以用一个关于密度算符的主方程来描述,比如,用来描述固态物理中耗散现象的Caldeira.Leggett主方程.虽然已经有人为了求解此主方程的约化密度矩阵的精确表达式而做过一些努力,但迄今还未见有解答.本文使用了一种全新的方法来求解Caldeira-Leggett方程,用这个新方法可以得到积分形式的显式表达.该方法的要点在于利用有序算符内积分技术把关于密度算符的微分方程首先转化成关于密度态矢量的微分方程,再将密度态矢量投影到热纠缠态表象中,Caldeira-Leggett方程就转变成了关于波函数的微分方程,而波函数是函数.这样就可以使用数学中求解微分方程的方法来求解出波函数.再次利用有序算符内积分技术,再将波函数转化为态矢量和算符,就得到了Caldeira-Leggett方程的积分形势解.     

新纠缠态表象的构建及其性质

运用有序算符内积分(IWOP)技术,构建了(x)2—p1和.(x)1—P2的共同本征态｜η〉,并分析了该新纠缠表象的Schmidt分解形式.另外,我们还得到纠缠态｜η>的共轭态｜ξ〉,同时计算了它们的内积.最后我们给出了新双模压缩算符S2=μ∫d2η/π｜μη〉〈η｜的显式,并分析了其压缩特性.     

激发纠缠相干态的统计性质

将玻色湮灭算符的逆算符作用在纠缠相干态的一个模上得到激发纠缠相干态.该量子态是玻色湮灭算符的偶次幂本征态;由于两个场模间的纠缠,在a模上增加光子不但可以使a模的平均光子数增加,也可以使b模的平均光子数发生变化;当a模上增加光子后,两个场模的亚泊松分布特性和Cauchy-Schwartz不等式的破坏都得到了增强,但模间反关联度反而减弱.     

论双模压缩算符的自然表象——纠缠态表象

利用简洁的幺正变换得到双模压缩算符在纠缠态中表示,使用同样的方法可得到双模压缩算符在坐标和动量本征态中的表示。     

相干态在算符正规排序中的应用

利用相干态的超完备性与有序算符内的积分技术,给出若干量子玻色算符的正规排序形式.与其他方法相比,此方法在理论应用中具有简捷明了的特点.     

Relationship Between Wave Function and Corresponding Wigner Function Studied in Entangled State Representation

By using the explicit form of the entangled Wigner operator and the entangled state representation we derive the relationship between wave function and corresponding Wigner function for bipartite entangled systems. The technique of integration within an ordered product （IWOP） of operators is employed in our discussions.     

Generalized Bargmann Representation of Spin Coherent State

Based on the conclusion that the generalized Bargmann representation of a two-mode Fock state is a two-variable Hermite polynomial function [Hong-Yi Fan and Jun-hua Chen, Phys. Lett. A303 (2002) 311] we derive the generalized Bargmann representation of the spin coherent state and some new relations in the generalized function space.     

Some New Properties of Wigner Function Studied in Entangled State Representation

Based on the Wigner operator in the entangled state representation we study some new important properties of Wigner function for bipartite entangled systems, such as size of an entangled state, upper bound of Wigner functions, etc. These discussions demonstrate the beauty and elegance of the entangled state representation.     

Nonlinear Tripartite Entangled State Representation and Related Generalized Wigner Function

We construct the nonlinear tripartite entangled state representation and the related generalized Wigner operator. Then we discussed the Wigner functions of the nonlinear tripartite entangled state and the three-mode nonlinear squeezed vacuum state, and obtained the classical Weyl corresponding function of the three-mode nonlinear squeezed state.     

Nonlinear Tripartite Entangled State Representation and Related Generalized Wigner Function

We construct the nonlinear tripartite entangled state representation and the related generalized Wigner operator. Then we discussed the Wigner functions of the nonlinear tripartite entangled state and the three-mode nonlinear squeezed vacuum state, and obtained the classical Weyl corresponding function of the three-mode nonlinear squeezed state.     

Pseudo-Classical Partition Function of Spin One-Half Derived by Coherent State Method

Using the bosonic coherent state representation and the Schwinger bosonic operator realization of angular momentum we find the formula for the quantum Hamiltonian H =iaiUijUjl a1 for SU（2） rotation U, in this way we further specify the angular velocity w, iUU = （1/2）σ·ω, where σ is the Pauli matrix. Though the spin as a quantum observable has no classical correspondence, we may still mimic it as a rigid body rotation characterized by 3 Euler angles, and calculate its Pseudo-classical rotational partition function of spin one-half.     

New Three-Mode Squeezing Operators Gained via Tripartite Entangled State Representation

We show that the Agarwal-Simon representation of single-mode squeezed states can be generalized to find new form of three-mode squeezed states. We use the tripartite entangled state representations ｜p, y, z） and ｜x, u, v） to realize this goal.     

A Kind of Four-Mode Nonlinear Entangled State Representation in Quantum Optics

Based on the technique of integration within an ordered product of nonlinear bosonic operators, we construct a new four-mode nonlinear entangled state | α,β,γ〉 _λ,μ in 4-mode Fock space, which can make up a complete set. Its properties and applications are discussed. A possible scheme to generate this state is also presented.     

Coordinate Eigenstate Representation in Noncommutative Space as a New Entangled State in Quantum Mechanics

For the first time we construct the eigenstate ｜τ〉 of noncommutatlve coordinate. It turns out that｜τ〉 is an entangled state in the ordinary space. Remarkably, its Schmidt decomposition has definite expression in the coordinate representation and the momentum representation. The 〈τ｜ representation can simplify some calculations for obtaining energy level of two-dimensional oscillator in noncommutative space.     

Study Hankel Transforms and Properties of Bessel Function via Entangled State Representation Transformation in Quantum Mechanics

In Phys. Lett. A 313 (2003) 343 we have found that the self-reciprocal Hankel transformation (HT) is embodied in quantum mechanics by a transform between two entangled state representations of continuum variables. In this work we study Hankel transforms and properties of Bessel function via entangled state representations' transformation in quantum mechanics.