依赖强度耦合的Λ型三能级Jaynes-Cummings模型的原子发射谱及腔场谱

在假设原子初始处于激发态并计入原子-场耦合强度依赖性的条件下,用本征函数法研究了Λ型三能级原子与单模腔场共振相互作用系统的原子发射谱和腔场谱。结果表明,基态能级裂距对谱结构有重要影响。发射谱和腔场谱的谱线随初场增强不发生合并现象,腔场谱对初场光子统计性质不敏感。     

光场及原子-光场耦合的非线性对腔内原子辐射谱的影响

研究了包括任意的光场非线性和原子光场非线性依赖强度耦合J-C(Jaynes-Cummings)模型中单原子的辐射谱,分析了上述非线性对辐射谱的影响.结果表明,原子的辐射谱强烈地依赖于光场的非线性项R(a⁺a)及原子光场非线性耦合因子f(a⁺a)的形式,其谱结构与标准J-C模型中原子的辐射谱明显不同.当腔内充满的非线性介质使得f(a⁺a)=1/(a⁺a)^1/2时,对于任意的初始光场态,辐射谱总是显示 关键词： 辐射谱 非线性耦合     

The physical transient spectrum for a V-type three-level atom interacting with a binomial field via multi-photon process and nonlinearities

We study the interaction of a multi-photon three-level atom with a single mode field in a cavity, taking explicitly into account the existence of forms of nonlinearities of both the field and the intensitydependent atom-field coupling. The analytical form of the emission spectrum is calculated using the dressed states of the system. The effects of photon multiplicities, mean photon number, detuning, Kerr-like medium, and the intensity-dependent coupling functional on the emission spectrum are analyzed.     

压缩真空场与原子非线性作用系统中原子的量子特性

研究了附加克尔介质的压缩真空场与二能级原子依赖强度耦合相互作用系统中原子的反转特性,并采用密度算符间的距离研究了该模型中原子量子态的演化规律.详细地讨论了克尔非线性作用的强度以及初始压缩真空场的压缩度对原子反转和原子量子态演化的影响.     

Entanglement of a General Formalism V-Type Three-Level Atom Interacting with a Single-Mode Field in the Presence of Nonlinearities

We investigate the evolution of the atomic quantum entropy and the atom-field entanglement in a system of a V-configuration three-level atom interacting with a single-mode field with additional forms of nonlinearities of both the field and the intensity-dependent atom-field coupling. With the derivation of the unitary operator within the frame of the dressed state and the exact results for the state of the system we perform a careful investigation of the temporal evolution of the entropy. A factorization of the initial density operator is assumed, considering the field to be initially in a squeezed coherent or binomial state. The effects of the mean photon number, detuning, Kerr-like medium and the intensity-dependent coupling functional on the entropy are analyzed.     

Engineering transient spectrum for a two-level system interacting with two-mode intelligent states

The problem of a single two-level atom in its excited state, placed in a bimodal cavity in which an arbitrary form of the intensity-dependent atom–field coupling is present, is solved exactly. Expressions for the energy eigenvalues and eigenvectors are derived, and an exact representation for the time-dependent unitary evolution operator of the system is given, by means of which we analyze the analytic form of the fluorescence spectrum using the transitions among the dressed states of the system. The influence of parameter misfits on the quantum system is discussed. An interesting relation between the fluorescence spectrum and the dynamical evolution is found when the initial field states are prepared in properly intelligent states. By comparison with exact numerical results, we demonstrate that features of the fluorescence spectrum are influenced significantly by the different kinds of the nonlinearity of the intensity-dependent atom–field coupling. We provide numerous examples to illustrate this correspondence, and provide evidence of its usefulness. The present work considerably extends earlier results for two-level systems.     

Emission and absorption spectra of a general formalism Ξ-type three-level atom driven by a single-mode field with nonlinearities

We study the interaction of a three-level atom with a single-mode field in a cavity. We take explicitly into account the existence of the forms of nonlinearities of both the field and the intensity-dependent atom-field coupling. The wavefunction for the atomic system of the Ξ configuration is obtained when the atom is initially prepared in the excited state. The electromagnetic field may assume a squeezed coherent or binomial state. The analytical forms of the fluorescence and absorption spectra are calculated using the dressed states of the system. We investigate the influences of the mean number of photons, detunings, and the nonlinearities forms on the spectrum of the resulting field states. It is shown that the features of the fluorescence and absorption spectra are influenced significantly by the kinds of nonlinearities.     

Decay properties of a two-level atom in a non-resonant damped cavity

The upper state population evolution and the spontaneous emission spectrum of a two-level atom in a non-resonant damped cavity are investigated by using the resolvent operator. The analytic expressions of the spectrum and the upper state population with strong and intermediate coupling are obtained. The influence of coupling intensity and detuning on atomic spectrum is discussed. We find that the detuning affects strongly the shape of spectra.     

Emission and absorption spectra of a Λ type three-level atom driven by a two-mode cavity field with nonlinearities

An analytical expression of the emission and absorption spectra for a Λ type three-level cavity-bound atom interacting with a two-mode cavity field is given using the dressed states of the system. We take into account explicitly the nonlinearities of both the field and the intensity-dependent atom-field coupling. The characteristics of the emission and absorption spectra when one of the two-mode cavity fields is in a binomial state and the other is in a squeezed coherent state are exhibited. The effects of the mean number of photons, detuning, and the kinds of nonlinearities on the spectra are analyzed.     

Treatment of the emission and absorption spectra for a Λ-type three-level atom driven by a single-mode field with nonlinearities

The treatment of a Λ-type three-level atom interacting with a single mode field in a cavity, explicitly taking the existence of forms of nonlinearities of both the field and the intensity-dependent atom-field coupling into account. Analytical expressions of the emission and absorption spectra are presented using the dressed states of the system. The characteristics of the emission and absorption spectra for binomial state and squeezedcoherent state inputs are exhibited. The effects of the mean number of photons, the detuning, and the nonlinearities on the spectra are investigated. It is shown that the features of the fluorescence and absorption spectra are influenced significantly by the kinds of nonlinearities.     

A treatment of the emission and absorption spectra of a general formalism V-type three-level atom driven by a single-mode field with nonlinearities

A treatment of a V-type three-level atom interacting with a single mode field in a cavity, taking explicitly the existence of forms of nonlinearities of both the field and the intensity-dependent atom-field coupling into account. Analytical expressions of the emission and absorption spectra are presented using the dressed states of the system. The characteristics of the emission and absorption spectra for a binomial state and a squeezed coherent state inputs are exhibited. The effects of the mean number of photons, detuning and the nonlinearities on the spectra are investigated. It is shown that features of the fluorescence and absorption spectra are influenced significantly by the kinds of the nonlinearities.     

Quantum Entropy of a Four-Level Atom with Arbitrary Nonlinearities

General formalisms of a four-level atom in different configurations interacting with a single mode quantized electromagnetic field under multi-photon process with additional forms of nonlinearities of both the field and the intensity-dependent atom-field coupling are investigated. Analytical expressions for the time unitary evolution operator and density operator are obtained. The atom is prepared in its upper most and the field is prepared in a binomial state. The effects of the mean photon number, photon multiplicity, detuning, Kerr-like medium and the intensity-dependent coupling functional on the entropy are considered. General conclusions reached are illustrated by numerical results.     

Symmetric structure of the field and atomic squeezing in a quantum optical model

At resonance, the symmetric structure of the field and atomic squeezing has been exposed in the Jaynes-Cummings model when it is restricted to the following initial condition: the atom in the ground state and the field in the superposition of the vacuum and one-photon state. The influence of the detuning, the virtual-photon processes, intensity-dependent coupling and the presence of a Kerr-like medium on the symmetric structure has also been discussed.     

依赖强度耦合多光子过程中的缠绕与薛定谔猫态

通过研究领事强度耦合多光子过程中的光场熵演化和光场Ｑ函数，揭示了光场与原子的缠绕特性，讨论原子跃迁过程中吸收或发射的光子数对缠绕特性和薛定谔猫态的影响。     

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     

Entanglement of a multi-photon three-level atom interacting with a single-mode field in the presence of nonlinearities

General formalisms of a three-level atom in different configurations (namely, V, ??, and ?? configurations) interacting with multi-photon process of a single-mode field are investigated. Analytical expressions of the unitary operator within the framework of the dressed states and density operators of the consideration systems are derived. The temporal evolution of atomic quantum entropy when the field is initially in the binomial state and the atom is initially in its upper most state is considered. The effect of multiplicity, Kerr-like medium, detuning and different forms of intensity-dependent coupling functional on the degree of entanglement (DEM) are discussed. Details of the phenomenon differ from one configuration to the other.     

原子-场强度相关耦合时原子质心平移运动与内态布居的关系

基于原子与腔场共振相互作用及原子-场缀饰态,讨论了驻波腔场中两能级原子与场耦合强度相关时的原子质心的量子化平移运动对原子内态布居间的相互影响。结果表明原子平移运动敏感地依赖于原子的内态布居。特别地,当原子处于两内态等权重同位相迭加态时,平移运动呈现出很稳定的特征。     

Entropy squeezing for a two-level atom in the Jaynes－Cummings model with an intensity-depend coupling

We study the squeezing for a two-level atom in the Jaynes－Cummings model with intensity-dependent coupling using quantum information entropy, and examine the influences of the initial state of the system on the squeezed component number and direction of the information entropy squeezing. Our results show that, the squeezed component number depends on the atomic initial distribution angle, while the squeezed direction is determined by both the phases of the atom and the field for the information entropy squeezing. Quantum information entropy is shown to be a remarkable precision measure for atomic squeezing.     

理想腔中具有正交偶极矩的级联型三能级原子发射谱

假设原子具有两正交跃迁电偶极矩，运用全量子论研究了与单模电磁场共振相互作用的等距三能级原子的发射谱. 对不依赖于场强耦合和依赖强度耦合两种情况分别进行了发射谱的计算，并比较了原子偶极矩正交和平行条件下发射谱的异同. 结果表明，一般情况下，具有平行偶极矩的原子的发射谱谱线少于具有正交偶极矩的原子的谱线，一些谱线由于干涉而消失. 关键词： 量子光学 发射谱 电偶极矩 级联型三能级原子     

附加Kerr介质依赖强度耦合负二项式光场与二能级原子的相互作用

采用数值计算的方法,研究了有Kerr介质存在时负二项式光场与二能级原子依赖强度耦合相互作用系统中原子布居反转的时间演化规律,讨论了Kerr介质和光场参量对原子反转的时间演化的影响.