双模Jaynes-Cummings模型中原子偶极压缩与双模光场压缩间的关联

通过考察双模Ｊａｙｎｅｓ－Ｃｕｍｍｉｎｇｓ（Ｊ－Ｃ）模型中原子偶极压缩和双模光场二阶压缩以及原子振幅平方压缩与双模光场高阶压缩随时间的演化规律，研究了原子偶极压缩和双模光场二阶压缩之间的关系，讨论了原子振幅平方压缩与双模光场高阶压缩之间的联系，并探讨了原子偶极压缩与双模光场压缩之间相互转化的特征。     

依赖于时间和强度耦合J-C模型中原子偶极压缩特性

研究了依赖于时间和强度耦合J-C模型中原子的偶极压缩现象。并详细讨论了原子与腔场以时间脉冲形式耦合时,脉冲宽度和腔场强度对原子算符压缩的影响。结果表明,在此模型下原子的偶极压缩随时间的演化特性与其他强度耦合模型明显不同,而且可以通过调节脉冲宽度有效控制原子的偶极压缩程度。     

与量子光场相互作用的运动原子的熵压缩

运用量子信息熵理论,研究了与量子光场相互作用的二能级运动原子的熵压缩,讨论了原子运动和场模结构对原子熵压缩的影响,并且比较了分别从基于信息熵测不准关系和海森伯测不准关系出发得出的结果,表明原子的运动导致了原子熵压缩的周期性演化;随着场模结构参量的增大,熵压缩的演化周期缩短,压缩时间延长;选择适当的系统参量,运动原子能够呈现长时间的持续熵压缩效应。当原子反转为零时,基于海伯堡测不准关系的方差压缩定义不再有效,而熵压缩实现了对原子压缩效应的高灵敏量度。     

三能级原子系统中原子偶极压缩和光场压缩间的关联

通过考察三能级原子与单模和双模场相互作用系统中原子偶极压缩和光场压缩随时间的演化规律, 研究了原子偶极压缩与光场压缩之间的关系, 讨论了原子偶极压缩与光场压缩之间相互转换的特征, 并给出了初始处于偶极压缩状态的原子辐射压缩光的条件。     

Single-atom entropy squeezing and quantum entanglement in Tavis--Cummings model with atomic motion

We examine the single-atom entropy squeezing and the atom-field entanglement in a system of two moving twolevel atoms interacting with a single-mode coherent field in a lossless resonant cavity.Our numerical calculations indicate that the squeezing period,the squeezing time and the maximal squeezing can be controlled by appropriately choosing the atomic motion and the field-mode structure.The atomic motion leads to a periodical time evolution of entanglement between the two-atom and the field.Moreover,there exists corresponding relation between the time evolution properties of the atomic entropy squeezing and that of the entanglement between the two atoms and the field.     

原子的选择电离和测量对腔场压缩性质的影响

研究了里德伯原子与腔场发生相互作用后腔场的压缩性质.结果表明,对不同的原子进行选择电离和测量腔场的压缩性质不同.且最大压缩处压缩参量可达25%.     

Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

In this paper, we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling. We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially. The effects of the field squeezing factor, the two-level atomic transition frequency, the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed. Without intrinsic decoherence, the increase of field squeezing factor can break the entropy squeezing. The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing. The influence of the second field frequency is complicated. With the intrinsic decoherence taken into consideration, the results show that the stronger the intrinsic decoherence is, the more quickly the entropy squeezing will disappear. The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing.     

双模纠缠相干场控制下的双光子过程中有效二能级原子的信息熵压缩

根据量子信息理论,研究了与双模纠缠相干场相互作用双光子过程中有效二能级原子的信息熵压缩。讨论了场的初态对信息熵压缩的因影响,并且比较了分别从基于信息熵测不准关系和海森堡测不准关系出发得出的结果。结果表明：信息熵压缩的稳定周期性、压缩方向分别由场的平均光子数和方向角控制. 在强场条件下, 场的纠缠度对信息熵压缩不产生影响。当原子反转为零时,基于海森堡测不准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.     

两偶极相互作用原子系统中的偶极平方压缩

研究了两个存在偶极相互作用的原子系统中的偶极平方压缩效应,讨论了原子偶极相互作用以及相位信息对压缩效应的影响,并进而探讨了原子偶极平方压缩与光场振幅平方压缩之间的关联.     

Field and dipole squeezing in a driven degenerate Λ quantum-beat system

The properties of field squeezing and atomic dipole squeezing in a coherent-microwave field driven degenerate Λ quantum-beat system were theoretically investigated. Numerical calculations indicate that the driving microwave may enhance or suppress both dipole squeezing and cavity-field squeezing, depending on the atomic energy level splitting and the microwave Rabi frequency.     

The effect of the counter-rotating terms on the squeezing in the Jaynes-Cummings model for a coherent field

Summary The effect of the counter-rotating terms on the squeezing in the Jaynes-Cummings model is demonstrated. The time behaviour of the atomic population inversion, atomic and field squeezing parameters for an initially coheret field is calculated numerically.     

Information Entropy Squeezing for a Atom in Mode-Mode Competition System

The entropy squeezing properties for a two-level atom interacting with a two-mode field via two different competing transitions are investigated from a quantum information point of view. The influences of the initial state of the system and the relative coupling strength between the atom and the field on the atomic information entropy squeezing are discussed. Our results show that the squeezed direction and the frequency of the information entropy squeezing can be controlled by choosing the phase of the atom dipole and the relative competing strength of atom-field, respectively. We find that, under the same condition, no atomic variance squeezing is predicted from the HUR while optimal entropy squeezing is obtained from the EUR, so the quantum information entropy is a remarkable precision measure for the atomic squeezing in the considered system.     

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     

Non—conservation of energy arising from atomic dipole interactions and its effects on light field and coupled atoms

The interactions between coupled atoms and a single mode of a quantized electromagnetic field, which involve the terms originating from the dipole interactions, are discussed. In the usual Jaynes－Cummings model for coupled atoms, the terms of non-conservation of energy originating from dipole interactions are neglected, however, we take them into consideration in this paper. The effects of these terms on the evolutions of quantum statistic properties and squeezing of the field, the squeezing of atomic dipole moments and atomic population inversion are investigated. It has been shown that the coupling between atoms modulates these evolutions of fields and atoms. The terms of non-conservation of energy affect these evolutions of fields and atoms slightly. They also have effects on the squeezing of the field, the squeezing of atomic dipole and atomic population inversions. The initial states of atoms also affect these properties.     

Finite periodic and quasiperiodic systems in an electric field

In this paper, we have studied the field and atomic dipole squeezing in the two-photon Jaynes-Cummings model when it is restricted to the following initial condition: the field in the thermal state and the atom in a coherent state. The relationship between the field and atomic dipole squeezing has also been discussed in detail.     

Entropy squeezing of a moving atom and control of noise of the quantum mechanical channel via the two-photon process

Based on the quantum information theory, we have investigated the entropy squeezing of a moving two-level atom interacting with the coherent field via the quantum mechanical channel of the two-photon process. The results are compared with those of atomic squeezing based on the Heisenberg uncertainty relation. The influences of the atomic motion and field-mode structure parameter on the atomic entropy squeezing and on the control of noise of the quantum mechanical channel via the two-photon process are examined. Our results show that the squeezed period, duration of optimal entropy squeezing of a two-level atom and the noise of the quantum mechanical channel can be controlled by appropriately choosing the atomic motion and the field-mode structure parameter, respectively. The quantum mechanical channel of two-photon process is an ideal channel for quantum information (atomic quantum state) transmission. Quantum information entropy is a remarkably accurate measure of the atomic squeezing.     

双模纠缠相干光场控制下双光子过程中有效二能级原子的信息熵压缩

根据量子信息理论,研究了与双模纠缠相干场相互作用双光子过程中有效二能级原子的信息熵压缩.讨论了场的初态对信息熵压缩的因影响,并且比较了分别从基于信息熵测不准关系和海森堡测不准关系出发得出的结果.结果表明:信息熵压缩的稳定周期性、压缩方向分别由场的平均光子数和方向角控制,场的纠缠度对信息熵压缩不产生影响.信息熵压缩实现了对原子压缩效应的高灵敏量度.     

强场与级联型三能级原子相互作用中原子的偶极压缩效应

采用数值计算方法研究了强相干初态光场与级联型三能级原子相互作用中原子的偶极压缩效应结果表明:级联型三能级原子偶极算符的两个正交分量均呈现出周期性的压缩现象,原子存在偶极压缩,且压缩的最大深度比弱场作用情况下要深得多;随着n值的不断增大,偶极算符两个正交分量的振荡频率随之增大,场与原子的非线性耦合越来越强,且振荡重复地出现复苏缩现象.     

与二项式光场相互作用的运动原子熵压缩

运用量子信息熵理论,研究了二项式光场与运动二能级原子相互作用过程中运动原子的信息熵压缩。讨论了不同的原子初态和场的有关参数对原子信息熵压缩的影响。结果表明：选择原子初态、场模结构、场调节参数及原子运动速度可以调控原子信息熵的压缩方向、偶极矩分量值和压缩周期;适当的选择参数可得到持续性的原子信息熵压缩。