基于Jaynes-Cummings模型的量子参数估计与初态优化

参数估计理论是根据实验测量数据推断物理模型中未知参数的重要理论工具.Jaynes-Cumming模型是量子光学中广泛使用的模型,描述了二能级原子和单模量子光场之间的相互作用.利用参数估计理论系统地研究了该模型中光-原子耦合强度g的估计精度,并找到了可达到最高估计精度的初态.该结果可以提高基于Jaynes-Cumming模型的量子精密测量的精度,该研究方法也可用于其他基于混合量子系统的量子度量学研究.

退相干演化对Jaynes-Cummings模型影响的考察

使用混态演化的Kraus求和方法,考虑在退极化模式下,基于Jaynes-Cummings模型设定初态,对退相干时间演化后末态的保真度与von Neumann熵的变化进行了讨论分析.结果表明,存在退相干演化的量子态保真度会随时间发生衰减振荡至稳定,而von Neumann熵会随时间发生振幅减小的振荡变化.

Entropy squeezing of an atom with a k-photon in the Jaynes-Cummings model

The entropy squeezing of an atom with a k-photon in the Jaynes Cummings model is investigated. For comparison, we also study the corresponding variance squeezing and atomic inversion. Analytical results show that entropy squeezing is preferable to variance squeezing for zero atomic inversion. Moreover, for initial conditions of the system the relation between squeezing and photon transition number is also discussed. This provides a theoretical approach to finding out the optimal entropy squeezing.

Level crossing in a two-photon Jaynes-Cummings model

In this paper,the energy spectrum of the two-photon Jaynes-Cummings model（TPJCM） is calculated exactly in the non-rotating wave approximation（non-RWA）,and we study the level-crossing problem by means of fidelity.A narrow peak of the fidelity is observed at the level-crossing point,which does not appear at the avoided-crossing point.Therefore fidelity is perfectly suited for detecting the level-crossing point in the energy spectrum.

Squeezing effect of the cavity field in the two-atom Jaynes-Cummings model

Authors investigate the model that two two level atoms interact with a single mode cavity. The formulation of the time evolution operator for the two atom Jaynes Cummings model is presented by the bare states approach. Besides, squeezing effect of the cavity field is studied and some novel features are obtained.

Dynamics of Jaynes-Cummings Model in the Absence of Rotating-Wave Approximation

Jaynes-Cummings 模型(JCM ) 被一种协调状态的扩大技术当 therotating 波浪近似(RWA ) 不在时学习。与协调状态的扩大仅仅在被执行到第三份订单的以前的纸比较，我们在这篇论文的供打包的酒菜没有 theRWA，确切表明 JCM 的动力学的完全的扩大。我们的学习给一个系统的方法解决 non-RWA 问题，它将在各种各样的 physicai 系统是有用的，例如，在有 uitracold 的一个系统，套住的离子经历跑激光飘动。

Photon statistical properties of the cavity field in the two-atom Jaynes-Cummings model

The model that two two level atoms interact with a singel mode cavity is studied. The exact solution of the time evolution operator for the two atom Jaynes Cummings model is presented by the bare states approach. Furthermore, we investigate the dynamical properties of the photon statistics of the cavity field, and obtain a number of novel features.

Pseudo-invariant Eigen-operator for Deriving Energy-Level Gap for Jaynes-Cummings Model

我们通过分析标准 Jaynes-Cummings 模型扩大不变的 eigen 操作员的概念到 pseudo-invarianteigen-operator 大小写。我们以这个模型的超级对称的发电机发现 thepseudo 不变的 eigen 操作员，哪个到为 Jaynes-Cummings Hamiltonian 的精力级的差距的 diretlyleads。

Coherence Loss of Two-Photon Jaynes-Cummings Model in Dispersive Approximation

Completely solving the dissipative dynamics of nonlinear Jaynes-Cumming model is a very difficult task.In our recent work (Phys. Lett. A284 (2001) 156), we just obtained analytical results of the field dissipative dynamicsof the nonlinear JCM. In the present paper, employing the perturbative expansion of master equation, we obtain thedensity operator of the system (field +atom). The coherence losses of the system and of the atom are investigated whentwo-photon process is involved. We also study the effect of different atomic initial states and the influence of the fieldamplitude on the atomic coherence loss.

Geometric Phase in a Time-Dependent A-Type Jaynes-Cummings Model

由使用路易斯·里森菲尔德不变的理论，我们学习了动态并且在概括时间依赖者 Λ-type 贾内斯·卡明斯的几何阶段当模特儿。我们发现与动态阶段相比，在一个周期盒子中的几何阶段独立于光子领域，在光子和原子之间的联合系数，和原子转变频率的频率。在一个周期盒子中的几何阶段能在一块更强壮的时间依赖者光子地和一个更强壮的联合光子原子系统的盒子下面被测量，这被指出。在另一方面，模型的几何阶段可以在冷原子的作文被测量。

Two-Photon Jaynes-Cummings Model Governed by Milburn Equation with Phase Damping

<正> In this paper,we find an analytic solution of the master equation of a non-resonant two-photon Jaynes-Cummings model(JCM)with phase damping with the help of the super-operator technique.We study the influence ofphase damping on non-classical effects in the JCM,such as oscillations of the photon-number distribution,revivals of theatomic inversion,and sub-Possion photon statistics.It is demonstrated that the phase damping suppresses the revivalsof the atomic inversion and non-classical effects of the cavity field in the JCM.

Exact Solution for Jaynes-Cummings Model with Bosonic Field Nonlinearity and Strong Boson-Fermion Coupling

当 strongboson 费米子政变石楠是珍视的无有势力 Grassmann 时，我们使用对待 modifiedJaynes-Cummings 的不变的途径建模包含 bosonic 域的 nonlinearty 的任何表格的 Lewis-Riesenfeld。为 bosonic 号码和 fermionic 号码的一般州的函数，时间进化操作符和时间进化表达式被介绍。

Pseudo-invariant Eigen-Operator Method for Solving Field-Intensity-Dependent Jaynes-Cummings Model

By using the pseudo invariant eigen-operator method we analyze the field-intensity-dependent JaynesCumming (JC) model. The pseudo-invariant eigen-operator is found in terms of the supersymmetric generators. Theenergy-level gap of this JC Hamiltonian is derived. This approach seems concise.

Partial entropy change and entanglement in the mixed state for a Jaynes-Cummings model with Kerr medium

By using the algebraic dynamical approach, an atom--field bipartite system in mixed state is employed to investigate the partial entropy change and the entanglement in a cavity filled with Kerr medium. The effects of different nonlinear intensities are studied. One can find that the Kerr nonlinearity can reduce the fluctuation amplitudes of the partial entropy changes and the entanglement of the two subsystems, and also influence their periodic evolution. Meanwhile, increasing the Kerr nonlinear strength can convert the anti-correlated behaviour of the partial entropy change to the positively correlated behaviour. Furthermore, the entanglement greatly depends on the temperature. When the temperature or the nonlinear intensity increases to a certain value, the entanglement can be suppressed greatly.

Properties of Linear Entropy in k-Photon Jaynes-Cummings Model with Stark Shift and Kerr-Like Medium

The time evolution of the linear entropy of an atom in k-photon Jaynes-Cummings model is investigatedtaking into consideration Stark shift and Kerr-like medium. The effect of both the Stark shift and Kerr-like medium onthe linear entropy is analyzed using a numerical technique for the field initially in coherent state and in even coherentstate. The results show that the presence of the Kerr-like medium and Stark shift has an important effect on theproperties of the entropy and entanglement. It is also shown that the setting of the initial state plays a significant rolein the evolution of the linear entropy and entanglement.

The two-atom Jaynes-Cummings model's dynamic properties

The model of two two level atoms interact with a single mode cavity was investigated. The formulation of the time evolution operator for the two atom Jaynes Cummings model is pressented by the bare states approach. Besides, the time evolution of the two atom common population probabilities is studied, and some novel features are obtained.

Entanglement dynamics of a double two-photon Jaynes-Cummings model with Kerr-like medium

In this paper, the entanglement dynamics of a double two-photon Jaynes-Cummings model with Kerr-like medium is investigated. It is shown that initial entanglement has an interesting subsequent time evolution, including the so-called entanglement sudden death effect. It is also shown analytically that the Kerr-like medium can repress entanglement sudden death and enhance the degree of atom-atom entanglement. A more interesting fact is that the Kerr effect is more obvious when each of the two cavities with have the Kerr-like medium than only one of them with the Kerr-like medium.

Properties of field quantum entropy evolution in the Jaynes-Cummings model with initial squeezed coherent states field

The properties of the field quantum entropy evolution in a system of a single-mode squeezed coherent state field interacting with a two-level atom is studied by utilizing the complete quantum theory, and we focus our attention on the discussion of the influences of field squeezing parameter γ, atomic distribution angle θ and coupling strength g between the field and the atom on the properties of the evolution of field quantum entropy. The results obtained from numerical calculation indicate that the amplitude of oscillation of field quantum entropy evolution decreases with the increasing of squeezing parameter γ, and that both atomic distribution angle θ and coupling strength g between the field and the atom can influence the periodicity of field quantum entropy evolution.

Entropy evolution of field with a time-varying frequency in the Jaynes-Cummings model

Following Jaynes-Cummings model,the evolution of the field entropy in the system of a two-level atom interacting with the single mode coherent field is investigated under rotating-wave approximation.The typical case "the field frequency variance with time in the form of sine ω=ω0+usin(wt) has been considered.The influences of the amplitude and angle frequency of the field frequency variance on entropy evolution of the field are discussed by numerical calculations.Calculation results indicate that the field frequency variance influences violently the behavior of field entropy evolution;the larger the amplitude of the field frequency variance is,the stronger the influence of the field frequency variance on the time evolution of field entropy is.

Solving the Jaynes-Cummings Model with Shift Operators Constructed by Means of the Matrix-Diagonalizing Technique

The Jaynes-Cummings model is solved with the raising and lowering（shift） operators using the matrix-diagonalizing technique. Bell nonlocality is also found to be present ubiquitously in the excitation states of the model.