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.     

偶奇相干态的q-类比

在偶奇相干态的基础上,构造出偶、奇q-相干态,并讨论了它们的光统计特性.计算分析表明:偶奇q-相干态的光统计特性,是完全不相同的.     

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     

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|.     

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.     

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     

减光子偶、奇相干态及其量子统计特性

最近,XIN Zong-zheng等研究了玻色产生算符+重复作用k次下通常偶、奇相干态|α>e,o的光子激发态|α,+k>～+k|α>o,e的非经典特性[J. Phys. B29 1996) 2597]. 本文讨论|α>e,o在玻色产生算符的逆算符+-1重复作用于k次下的光子湮灭态|α,-k>～+-k|α>o,e的量子统计特性.     

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     

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.     

双曲正弦、余弦算符与奇偶相干态

利用Fock空间的平移算符引入了双曲正弦和余弦算符,该算符作用在真空态上给出奇相干态和偶相干态的一种新表示形式,并讨论了奇、偶相干态的准概率分布函数和非经典特性．     

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 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.     

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。     

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     

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.     

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.     

Decoherence of quantum excitation of even/odd coherent states in thermal environment

In this paper, we study the decoherence of quantum excitation (photon-added) even /odd coherent states, \(((\hat a{^{\dagger }})^{m} \left | {\alpha _ \pm } \right \rangle )\), in a thermal environment by investigating the variation of negative part of the Wigner quasidistribution function vs. the rescaled time. For this purpose, at first we obtain the time-dependent Wigner function corresponding to the mentioned states in the framework of standard master equation. Then, the time evolution of the Wigner function associated with photon-added even /odd coherent states, as well as the number of added photons m are analysed. It is shown that, in both states, the negative part of the Wigner function decreases with time. By deriving the threshold value of the rescaled time for single photon-added even /odd coherent states, it is also found that, if the rescaled time exceeds the threshold value, the associated Wigner function becomes positive, i.e., the decoherence occurs completely.     

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     

Even and odd nonlinear coherent states

New types of even and odd nonlinear coherent states are defined. The squeezed vacuum and the squeezed first excited state are shown to be even and odd nonlinear coherent states, respectively. The nonclassical properties of some related states are studied.     

Phase properties of odd and even circular states

Phase properties of the even and odd circular states are studied within the Hermitian phase formalism of Pegg and Barnett. Exact analytical formulas for the distribution function and the variance of the phase operator are obtained and used to examine whether or not the even and odd circular states exhibit photon-number squeezing and phase squeezing.