利用分束器通过条件测量制备非经典光场态和量子纠缠态

把相干态和单粒子数态作为分束器的输入态，通过条件测量可以剪去输入相干态中的任意粒子数态，并研究了这些被剪切了的光场态的性质。结果显示剪去真空态和单粒子数态的输出态具有较强的压缩和亚泊松分布等非经典效应。把剪切了的输出态和真空态输入分束器，得到的输出态具有量子纠缠性质，从而制备出量子纠缠态，同时也验证了被剪切的输出态的非经典性。     

振幅相干态的量子统计性质

对振幅相干态|ψ＞的非经典性质进行了研究，用数值计算的方法讨论了它的振幅压缩性质、亚泊松分布特性和反聚束效应。     

非线性Trio-相干态的非经典特性

引入了非线性Trio-相干态,讨论了该量子态的完备性及其光子数统计分布和Cauchy-Schwarz不等式.结果表明,该量子态是超完备的,并且存在亚泊松统计分布和违背Cauchy-Schwarz不等式等非经典特性.     

正交相干态的非经典特性

本文研究了正交相干态的非经典特性。结果表明,正交相干态仅为光场振幅偶次幂的最小测不准态,无高阶压缩效应,但存在高阶反聚束效应和亚泊松分布。     

Glauber相干态的激发态及其非经典效应

构造了Glauber相干态的激发态,数值计算表明该激发态不仅显示反聚束效应,也呈现亚泊松分布.     

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     

偶奇qs相干态的非经典特性

利用数值计算方法研究了ｑ和ｓ畸变对双参数形变偶奇ｑｓ相干态量子统计特性的委现偶奇ｑｓ相干态与通常的偶奇相干态有着显著不同的量子统计性质，压缩效应和反聚束效应均可在一定条件下的两种双参数畸变态中出现，偶奇ｑｓ相干态和通常偶奇相干态的差异随ｑ值偏离１越大和ｓ的取值越小而越大。     

增光子圆态及其性质

利用光场产生算符的逆算符作用于圆态来构造增光子圆态.讨论了此态的非经典性质,同时计算并模拟出它的维格纳(Wigner)函数.结果表明,在不同光强下,随着激发数的增大增光子圆态光场的平均光子数增加与减少交替地出现;光子激发后,光场的亚泊松统计特性得到增强,压缩效应却受到抑制.维格纳函数图像显示了增光子圆态显著的非经典性质,发现了光子激发与圆态光强的增大都能使量子态由叠加引起的干涉效应明显增强.另外,在不同叠加数的情况下,通过适当选择参量可使维格纳函数具有相同的变化规律.     

广义压缩粒子数态的非经典性质及其退相干

研究了三参数的压缩算符产生的广义压缩粒子数态的非经典性质及其在光子损失通道中的退相干问题.利用有序算符内的积分技术和Weyl编序算符在相似变换下的不变性,简洁地导出了广义压缩粒子数态的Wigner函数(Laguerre-Gaussian函数).基于Wigner函数的演化积分公式,解析地推导出了在耗散通道中的Wigner函数表达式.特别地,根据Wigner函数负部体积讨论了其非经典性.     

纠缠双原子和相干光场作用的光子统计非经典特性

采用数值计算法研究了纠缠双原子和相干光场相互作用中辐射光场光子数分布的演化特性。结果表明,通过和纠缠双原子的相互作用,使得不具有反聚束效应和光子亚泊松分布的相干光场获得了非经典特性。并且初始双原子间的纠缠强度越大,辐射光场的非经典性质越强,说明可以通过选择初始原子状态制备非经典辐射光场。     

New Even and Odd Nonlinear Coherent States and Their Nonclassical Properties

Based on Roy and Roy's work (Roy, B. and Roy, P. (2000). Journal of Optics B: Quantum Semiclass. Opt. 2, 65), a new type of even and odd nonlinear coherent states (NCSs) are defined. They result from Schrödinger cat states for deformed field. Using the numerical method, we study nonclassical properties of the new even and odd NCSs. It is shown that quantum statistical properties of the new even and odd NCSs are quite different from those of the usual even and odd coherent states (CSs). It is found that the squeezing only consists in the new even NCS, and the amplitude-squared squeezing and antibunching effect appear for both new even and odd NCSs in some ranges of ||.     

A Class of Even and Odd Nonlinear Coherent States and Their Properties

A class of even and odd nonlinear coherent states are introduced. The properties of some related states, including quadrature squeezing, antibunching effect, and phase probability distribution, are studied.     

A Class of Even and Odd Nonlinear Coherent States and Their Properties

A class of even and odd nonlinear coherent states are introduced. The properties of some related states, including quadrature squeezing, antibunching effect and phase probability distribution, are studied.     

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。     

Nonlinear Quantum Optical Springs and Their Nonclassical Properties

The original idea of quantum optical spring arises from the requirement of quantization of the frequencyof oscillations in the Hamiltonian of harmonic oscillator. This purpose is achieved by consideringa spring whose constant (and so its frequency) depends on the quantum states of another system.
Recently, it is realized that by the assumption of frequencymodulation ofω toω(1+μa^\dagger a)^1/2the mentioned idea can be established.
In the present paper, we generalize the approach of quantum optical springwith particular attention to thedependence of frequency to the intensity of radiation fieldthatnaturally observes in thenonlinear coherent states}, from which we arrive ata physical system has been called by us as nonlinear quantum optical spring.Then, after the introduction of the generalized Hamiltonian of nonlinear quantum optical spring and it's solution,we will investigate the nonclassical properties of the obtained states. Specially, typical collapse and revivalin the distribution functions and squeezing parameters, as particular quantum features, will berevealed.     

Quantum Statistical Properties of k-Quantum Nonlinear Coherent States

In our preceding work, a class of k-quantum nonlinear coherent states, i.e., the k eigenstates of the powersBk (k ≥ 3) of the annihilation operator B=-a1/f(N) of f-oscillators, are introduced. In this paper, we introduce a newkind of higher-order squeezing and an antibunching effect. The quantum statistical properties of the k states are studied.The result shows that the M-th order [M = (n 1/2)k; n = 0, 1,...] squeezing effects exist in all of the k states when kis even. There is the antibunching effect in all of the k states.     

Quantum Statistical Properties of k-Quantum Nonlinear Coherent States

In our preceding work, a class of k-quantum nonlinear coherent states, i.e., the k eigenstates of the powers B^^k (k≥3) of the annihilation operator B^ =a^ 1/f(N^) of f-oscillators, are introduced. In this paper, we introduce a new kind of higher-order squeezing and an antibunching effect. The quantum statistical properties of the k states are studied. The result shows that the M-th order [M=(n 1/2)k; n=0, 1,...] squeezing effects exist in all of the k states when k is even. There is the antibunching effect in all of the k states.     

Odd-Excited Binomial States of the Radiation Field and Some of Their Statistical Properties

In this paper a new state called odd-excited binomial state (OEBS) is introduced. It interpolates between the odd number state and the odd-excited coherent state. We discuss some statistical properties, such as the Glauber second-order correlation function and squeezing phenomenon (normal and amplitude-squared squeezing) for this state. The quasiprobability distribution functions (Husimi Q-function and Wigner W-function) are also examined.     

New Even and Odd Nonlinear Coherent States and Their Nonclassical Properties

In this paper, a new kind of even and odd nonlinear coherent states (NLCSs) are introduced. Some nonclassical properties of the states are investigated. It has been found that the new even and odd NLCSs exhibit quadrature squeezing and amplitude-squared squeezing in the Y ₂ direction, however the new odd NLCSs only display sub-Poissonian behaviour. The results show that the nonclassical properties of the new even and odd NLCSs are rather different from those of the usual even and odd coherent states and NLCSs. PACS numbers:42.50.-p, 03.65.-w