位相相干态的数相高阶压缩

本文根据Ｐｅｇｇ－Ｂａｒｎｅｔｔ的量了相位理论和Ｈｏｎｇ－Ｍａｎｄｅｌ的高阶压缩概念，研究了有限维空间谐振子位相相干态中粒子数和相位的高阶压缩效应，研究结果表明，在特定的条件下，位相相干态的粒子数和相位都可呈出最大程度的高阶压缩。     

依赖强度耦合J-C模型中场的位相特性

应用Pegg-Barnett位相理论研究了依赖强度耦合JC模型中场位相的动力学和统计性质.在一定条件下,场可展示锁相和位相压缩效应以及保持光子数-位相最小确定态.     

量子隐形传态的新方案

提出一个量子隐形传态的新方案. 通过对一对压缩参数相同但相互独立的双模压缩真空态(1-2和3-4量子态系统)中的2-3系统施行粒子数-相位的联合测量,制备出另外两体系统(1-4系统)的纠缠态作为纠缠源,从而实现量子隐形传态. 关键词： 量子隐形传态 双模压缩真空态 纠缠态 粒子数-相位测量     

非线性压缩单光子态的位相概率分布

利用f-谐振子的产生和湮灭算符的逆算符，构造了两个非线性压缩单光子态，并借助于Pegg—Barnett位相算符公式和数值计算方法，研究了它们的位相概率分布。结果表明，两个非线性压缩单光子态的位相概率分布不同；与通常的压缩单光子态、非线性压缩真空态不同，在这两个非线性压缩单光子态中，其位相概率分布能明显地反映出不同的量子位相信息和干涉特性。     

运动原子与光场依赖强度纠缠下最佳熵压缩态的制备和控制

运用量子信息熵理论,研究了运动二能级原子与光场依赖强度纠缠下最佳熵压缩态的制备和控制;比较了分别从基于信息熵不确定关系和海森堡不确定关系出发得出的结果;分析了制备原子最佳熵压缩态的充要条件,并进行了数值验证.考察了场模结构参数对最佳熵压缩态的影响.结果表明,信息熵压缩是对原子压缩效应的高灵敏量度;控制原子与场的相互作用时间,斩断原子和场的纠缠,选择原子的相干性,调节系统的相对位相可制备原子最佳熵压缩态;控制场模结构参数,可获得持续的原子最佳熵压缩态. 关键词： 依赖强度耦合 场模结构参数 最佳熵压缩态     

双光子过程中任意初态原子的信息熵压缩

运用量子信息熵理论研究了双光子过程中任意初态二能级原子与相干场相互作用的信息熵压缩，讨论了系统初态对原子信息熵压缩的影响. 并且比较了分别从基于信息熵不确定关系和海森伯不确定关系出发得出的结果. 结果表明通过选择适当初始的原子分布角，原子的混合度和相干场的位相角，可以分别控制原子信息熵压缩的偶极矩分量数、压缩频率、压缩幅度和压缩方向. 当原子反转为零时，基于海森堡不确定关系的方差压缩定义不再有效，而信息熵压缩实现了对原子压缩效应的高灵敏量度. 关键词： 二能级原子 双光子过程 信息熵压缩 方差压缩     

超导约瑟夫森结在外光场下的数-相压缩效应

以约瑟夫森结为主要元件的量子计算机有广阔的应用前景.本文用纠缠态表象对超导约瑟夫森结进行研究,不但可以展现约瑟夫森结的隧穿电流,还能给出库珀对数-相的不确定关系.此基础上,探讨在外光场作用下约瑟夫森结的数-相压缩效应,即约瑟夫森结中的位相和库珀对数目的变化.同时推导出外光场作用下约瑟夫森结中的超导电流以及库珀对数-相所满足的不确定关系.     

利用分束器产生的一类非经典光场

把相干态和任意粒子数态作为分束器的输入态,通过条件测量可以得到被剪切了的输出态,并研究了这些剪切了的输出态的性质.结果显示,当在某一输出端测量到零个光子时,在另一输出端得到的剪切了的输出态呈现较强的压缩和亚泊松分布等非经典效应,并且这种非经典效应受输入粒子数态的粒子数的影响,即输入粒子数态的粒子数较大时其非经典性相对较强.当在其中一个输出端测量到m(m大于零)个光子时,条件测量后的各输出态在光场性质上表现类似,但也都呈现出明显的压缩和亚泊松分布等非经典效应,尤其值得注意的是当输入的是单粒子数态时,条件测量后的输出态中与测量相对应的粒子数态被剪去.     

在Jaynes—Cummings模型中压缩真空初态场位相演化特性

应用Ｐｅｇｇ－Ｂａｒｎｅｔｔ位相理论，研究了Ｊａｙｎｅｓ－Ｃｕｍｍｉｎｇｓ模型（Ｊ－Ｃ模型）中压缩真空初态场位相演化特性，具体计算了弱压缩条件下，场的位相几率分布函数及位相涨落，给出了在极坐标中位相几率分布演化曲线，讨论了原子与场相互作用对场的位相性质的影响。     

在Jaynes－Cummings模型中压缩真空初态场位相演化特性

应用Ｐｅｇｇ－Ｂａｒｎｅｔｔ位相理论，研究了Ｊａｙｎｅｓ－Ｃｕｍｍｉｎｇｓ模型（Ｊ－Ｃ模型）中压缩真空初态场位相演化特性，具体计算了弱压缩条件下，场的位相几率分布函数及位相涨落，给出了在极坐标中位相几率分布演化曲线，讨论了原子与场相互作用对场的位相性质的影响。     

Number-phase entropic uncertainty relations and Wigner functions for solvable quantum systems with discrete spectra

In this Letter, the “number-phase entropic uncertainty relation” and the “number-phase Wigner function” of generalized coherent states associated to a few solvable quantum systems with non-degenerate spectra are studied. We also investigate time evolution of “number-phase entropic uncertainty” and “Wigner function” of the considered physical systems with the help of temporally stable Gazeau-Klauder coherent states.     

Phase Properties of Photon-Added Coherent States for Nonharmonic Oscillators in a Nonlinear Kerr Medium

The potential of nonharmonic systems has several applications in the field of quantum physics. The photonadded coherent states for annharmonic oscillators in a nonlinear Kerr medium can be used to describe some quantum systems. In this paper, the phase properties of these states including number-phase Wigner distribution function,Pegg-Barnett phase distribution function, number-phase squeezing and number-phase entropic uncertainty relations are investigated. It is found that these states can be considered as the nonclassical states.     

Generalized coherent states for solvable quantum systems with degenerate discrete spectra and their nonclassical properties

In this paper, the generalized coherent state for quantum systems with degenerate spectra is introduced. Then, the nonclassicality features and number-phase entropic uncertainty relation of two particular degenerate quantum systems are studied. Finally, using the Gazeau-Klauder coherent states approach, the time evolution of some of the nonclassical properties of the coherent states corresponding to the considered physical systems are discussed.     

Number-phase uncertainty relationship for the nonlinear number-phasesqueezed state

For an harmonic oscillator with a field intensity related external source we establish the nonlinear number-phase squeezed state, in this state we find that while the number fluctuation increases, the phase fluctuation decreases correspondingly. The number-phase uncertainty relationship is exactly derived. In contrast to the usual coherent state which makes up the minimum number-phase uncertainty relationship, the nonlinear number-phase squeezed state does not reach its minimum uncertainty.     

Coherent States and Number-Phase Uncertainty Relations

The number-phase uncertainty relations arerevisited in view of the recent discovery of a propercovariant phase observable. The high-amplitude limits ofthe coherent-state expectations of the moment operators of the phase observable are determined and thebehavior of the number-phase uncertainty product in thatlimit is investigated.     

Amplitude squeezed and number-phase intelligent states via coherent state superposition

It is shown that Gaussian superpositions of coherent states along an arc are approximate number-phase intelligent states associated with the Pegg-Barnett phase operator and describe amplitude squeezing.     

一种新的非线性叠加相干态的相位特性

根据Pegg-Barnett 相位定义,计算了一种新的非线性叠加相干态的相位概率分布函数和光子数-相位压缩效应,并进行了数值模拟.     

Entropic uncertainty relations for nonextensive quantum scattering

In this paper the angle-angular momentum entropic uncertainty relations are obtained for Tsallis-like entropies for nonextensive quantum scattering of spinless particles. The number-phase entropic uncertainty relations are also proved for nonextensive quantum scattering. Numerical results on the experimental tests of these entropic uncertainty relations, for the nonextensive (q≠1) statistics case are obtained by calculations of Tsallis-like scattering entropies from the 48 experimental sets of the pion-nucleus phase shifts.     

Number-Phase Quantization Scheme and the Quantum Effects of a Mesoscopic Electric Circuit at Finite Temperature

For L-C circuit, a new quantized scheme has been proposed in the context of number-phase quantization. In this quantization scheme, the number n of the electric charge q(q=en) is quantized as the charge number operator and the phase difference θ across the capacity is quantized as phase operator. Based on the scheme of number-phase quantization and the thermo field dynamics (TFD), the quantum fluctuations of the charge number and phase difference of a mesoscopic L-C circuit in the thermal vacuum state, the thermal coherent state and the thermal squeezed state have been studied. It is shown that these quantum fluctuations of the charge number and phase difference are related to not only the parameters of circuit, the squeezing parameter, but also the temperature in these quantum states. It is proven that the number-phase quantization scheme is very useful to tackle with quantization of some mesoscopic electric circuits and the quantum effects.