Phase properties of new even and odd nonlinear coherent states

A new kind of even and odd nonlinear coherent states (EONLCSs) is introduced. Using the Pegg-Barnett formalism of phase operator we study the phase probability distributions of the new kind of EONLCSs. The numerical computation results show that the phase probability distributions for the new EONLCSs can clearly exhibit the different features of quantum interference and distinct from those of the ordinary even and odd coherent states (EOCSs) and EONLCSs. Based on the phase probability distributions we investigate the phase and number squeezing of the new EONLCSs. It is found that these states exhibit number squeezing for different ranges of the parameter |λ|.     

Roy-型奇偶非线性相干态的位相概率分布

借助于数值计算方法，研究了Roy-型奇偶非线性相干态的位相概率分布特性.结果表明，它们的位相概率分布不同；与通常的奇偶相干态不同，在这种新的奇偶非线性相干态中，Pegg-Barnett位相概率分布能明显地反映出不同的量子干涉特性. 关键词： Roy-型奇偶非线性相干态 Pegg-Barnett位相算符公式 位相概率分布     

新的奇偶非线性相干态及其非经典性质

构造出了一种新的奇偶非线性相干态, 并借助于数值计算方法研究了它们的压缩、振幅平方压缩、反聚束和相位概率分布等非经典性质. 结果表明, 与通常的奇偶相干态和非线性奇偶相干态不同, 在参数|λ|的不同取值范围内, 新的奇偶非线性相干态在Y₁和Y₂两个方向均可呈现振幅平方压缩效应, 而压缩效应仅在偶非线性相干态的X₂方向上呈现, 反聚束效应仅在奇非线性相干态中呈现. 另外, 通过研究新的奇偶非线性相干态相位概率分布, 发现新的奇偶非线性相干态具有完全不同的量子干涉特性. 关键词： 新的奇偶非线性相干态 压缩效应 反聚束 相位概率分布     

Finite-dimensional even and odd nonlinear pair coherent states and their some nonclassical properties

In this paper a new class of finite-dimensional even and odd nonlinear pair coherent states （EONLPCSs）, which can be realized via operating the superposed evolution operators D±（τ） on the state ｜q, 0）, is constructed, then their orthonormalized property, completeness relations and some nonclassical properties are discussed. It is shown that the finite-dimensional EONLPCSs possess normalization and completeness relations. Moreover, the finite-dimensional EONLPCSs exhibit remarkably different sub-Poissonian distributions and phase probability distributions for different values of parameters q, η and ξ.     

一种新的奇偶非线性相干态及其量子统计性质

定义了一种新的奇偶非线性相干态即算符B2[B=af(N)]的两个正交归一本征态,利用数值计算方法研究了它们的量子统计性质.结果表明,与通常的奇偶相干态不同,在参数|β|变化的某些范围内,只有偶非线性相干态可以存在压缩效应,而振幅平方压缩和反聚束效应在这两个态中均可以呈现 关键词： 新的奇偶非线性相干态 压缩 振幅平方压缩 反聚束效应     

玻色算符的逆算符及其相关的奇偶相干态

利用玻色算符的逆算符a^^-1和a^^+-1，定义了一类新的奇偶相干态 ，即增、减光子奇偶相干态.它们分别是算符为a^^-ka^^k+2,a^^+-ka ^²a^^+k的本征态，可由a^^-k和a^^+-k分别作用于通常的奇偶相干态来产生. 数值计算结 果表明，这类新的奇偶相干态都是非经典的光场态，它们都能呈现出光子反群聚效应 关键词： 玻色算符的逆算符 奇偶相干态 光子反群聚效应 量子压缩效应     

有限维Hilbert空间Roy型奇偶非线性相干态的振幅平方压缩

构造出了有限维Hilbert空间Roy型奇偶非线性相干态, 讨论了它们的正交归一完备性和振幅平方压缩效应. 研究表明, 在此空间中Roy型奇偶非线性相干态是归一完备的, 但不具有正交性; 当复参数相位角θ满足一定条件时它们存在振幅平方压缩效应, 同时导出了压缩条件与参数s,r以及函数f(n)之间的关系. 最后借助于数值计算, 发现对于5维(或7维)Hilbert空间中Roy型偶(或奇)非线性相干态, 当参数θ和Lamb-Dike参数η取某一给定值时, 在参数r变化的不同取值范围内, 它们均可以呈现振幅平方 关键词： 有限维Hilbert空间 Roy型非线性相干态 奇偶非线性相干态 振幅平方压缩     

奇偶相干态的SU2变换

本文以奇偶相干态为基矢,通过SU_2变换,构造了a~2的各正交归一本征态组,并讨论了它们的非经典效应与SU_2群参数的关系.     

有限维奇偶对相干态的非经典性质

构造出了奇偶对相干态的指数形式, 并把奇偶对相干态推广至有限维Hilbert空间, 获得了有限维奇偶对相干态, 然后讨论了它们的正交归一完备性、反聚束效应和相位概率分布. 结果表明, 在此空间中奇偶对相干态具有归一完备性, 但不具有正交性. 借助于数值计算发现, 无论q取何值, 在参数|ξ|的不同取值范围内, 对于5维Hilbert空间中奇偶对相干态在模1和模2两个方向上均可呈现反聚束效应, 并且此双模光场的光子均是相关的. 而在7维Hilbert空间中，奇偶对相干态相位概率分 关键词： 有限维奇偶对相干态 反聚束效应 相位概率分布     

增、减光子奇偶相干态的Wigner函数

利用Fock态表象下的Wigner函数定义，重构了增、减光子奇偶相干态的Wigner函数，并据此 讨论了它们的非经典性质.结果表明：增光子奇偶相干态总呈现出非经典特征，而减光子奇 偶相干态分别仅在k为偶数和奇数时呈现出非经典特征. 关键词： 奇偶相干态 玻色算符的逆算符 Wigner函数     

Wigner functions and tomograms of the even and odd binomial states

Using the coherent state representation of Wigner operator and the technique of integration within an ordered product (IWOP) of operators, the Wigner functions of the even and odd binomial states (EOBSs) are obtained. The physical meaning of the Wigner functions for the EOBSs is given by means of their marginal distributions. Moreover, the tomograms of the EOBSs are calculated by virtue of intermediate coordinate-momentum representation in quantum optics.     

增光子奇偶相干态的相位特性

借助于Pegg-Barnett相位算符理论和数值计算方法,研究了增光子奇偶相干态的相位概率分布,在此基础之上,讨论了有关数算符和相位算符的压缩特性。结果表明,增光子奇偶相干态的相位概率分布与通常的奇偶相干态、非线性相干态不同,在这种新的奇偶相干态中,其Pegg-Barnett相位概率分布能明显地反映出不同的量子相位信息和干涉特性。同时发现,在参量α的某些不同的取值范围内,增光子奇偶相干态在数算符和相位算符分量上均存在压缩效应。     

Wigner function and Bell’s inequalities for even and odd coherent states

The Wigner function and the symplectic tomogram of an entangled quantum state, which is a superposition of the photon’s coherent states (even and odd coherent states), is studied. Photon statistics and violation of Bell’s inequality for the photon state are discussed.     

一种新的奇偶非线性相干态的位相统计性质

根据Pegg-Barnett位相定义, 计算了一种新的奇偶非线性相干态的位相概率分布函数, 利用数值计算方法研究了它们的位相统计性质. 数值计算结果表明：新的奇偶非线性相干态的位相特性与通常奇偶相干态的位相特性截然不同.     

Continuous-variable quantum teleportation of even and odd coherent states through varied gain channels

This paper has investigated quantum teleportation of even and odd coherent states in terms of the EPR entanglement states for continuous variables. It discusses the relationship between the fidelity and the entanglement of EPR states, which is characterized by the degree of squeezing and the gain of classical channels. It shows that the quality of teleporting quantum states also depends on the characteristics of the states themselves. The properties of teleporting even and odd coherent states at different intensities are investigated. The difference of teleporting two such kinds of quantum states are analysed based on the quantum distance function.     

介观 Josephson 结与激发偶奇相干态的相互作用

本文研究介观 Josephson 结与激发偶奇相干态的相互作用。研究了存在非经典光场时介观 Josephson 结中超导电流的一些特性，诸如崩塌与复苏现象，流压台阶特性，直流分量涨落以及超导电流的量子相干等。结果显示，超导电流的涨落及期望值可呈现直流分量。结果还显示稳态超导电流量，超导电流涨落的直流分量以及超导电流直流分量的关联函数等皆与光场的相位有关。     

Wigner functions and tomograms of the photon-depleted even and odd coherent states

Using the coherent state representation of Wigner operator and the technique of integration within an ordered product （IWOP） of operators, this paper derives the Wigner functions for the photon-depleted even and odd coherent states （PDEOCSs）. Moreover, in terms of the Wigner functions with respect to the complex parameter a the nonclassical properties of the PDEOCSs are discussed. The results show that the nonclassicality for the state ｜β, m〉o （or ｜β,m〉e） is more pronounced when m is even （or odd）. According to the marginal distributions of the Wigner functions, the physical meaning of the Wigner functions is given. Further, the tomograms of the PDEOCSs are calculated with the aid of newly introduced intermediate coordinate-momentum representation in quantum optics.     

Quasiprobability distributions of a new kind of even and odd nonlinear coherent states

Using a numerical computational method, quasiprobability distributions of new kinds of even and odd nonlinear coherent states (EONLCS) are investigated. The results show that the distributions of the new even nonlinear coherent states (NLCS) are distinct from those of the new odd NLCS and imply that the new EONLCS always exhibit some different nonclassical effects. Finally, with the aid of newly introduced intermediate coordinate-momentum representation in quantum optics, the tomograms of the new EONLCS are calculated. This is a new way of obtaining the tomogram function.     

Phase Properties of New Even and Odd Nonlinear Coherent States

Using the Pegg–Barnett formalism of phase operator, we obtain phase probability distributions of new even and odd nonlinear coherent states. It is shown that the distributions for the states are rather different, and unlike the case of ordinary even and odd coherent states the Pegg–Barnett distribution clearly reflects the different character of quantum interference in the case of the new even and odd coherent states.     

kth-order antibunching effect for a new kind of excited even and odd q-coherent states

A new kind of excited even q-coherent states (aq-1)m|αqe and excited odd q-coherent states (aq-1)m|αqo is constructed by acting with inverse boson operators on the even and odd q-coherent states. The m dependence of the kth-order antibunching effect is numerically studied for k = 2, 3, 4, 5.It is shown that the kth-order antibunching effect enhances as m increases. The larger k, the quicker the antibunching effect enhances.