含时谐振子系统的时间演化及压缩态

研究了有压缩和驱动项的含时谐振子系统的时间演化.通过适当选取厄密不变量，得到含时谐振子系统的量子态时间演化的封闭解及该系统的时间演化算符，给出产生压缩态的条件，得出驱动项不影响系统压缩态的结论. 关键词：     

广义含时谐振子的压缩态和压缩数态

文中研究了广义含时谐振子系统的不变量和不变量的一般形式，并利用基本不变量构造了此含时系统的压缩态和压缩激态。     

具有非线性两模场和原子与场非线性耦合的Jaynes-Cummings模型的解

利用Lewis和Riesenfeld不变量方法求解了具有任意非线性场和依赖任意强度耦合的多光子双模场与二能级原子相互作用的JC模型,得到原子一光场的态矢、时间演化算符、原子布居和双模场的光子数算符的演化式.     

频率随时间变化的受迫谐振子的压缩态和压缩数态

研究了频率随时间变化的受迫谐振子系统的不变量和不变量的一般形式,并利用基本不变量构造了此含时系统的压缩态和压缩数态.     

广义含时谐振子系统的精确解和压缩态

利用一系列幺正变换,求出了广义含时谐振子系统的精确解,并利用此精确解构造了此系统的压缩态。     

二模谐振子能谱研究

通过对非耦合谐振子系统能谱、非耦合与坐标耦合共同组成的谐振子系统能谱、非耦合与动量耦合共同组成的谐振子系统能谱、非耦合与坐标动量交叉耦合共同组成的谐振子系统能谱和非耦合与压缩项耦合共同组成的谐振子系统5种谐振子能谱进行求解时,通过分析比较发现:其一,对存在非对易参数的能级差的解时,当非对易参数为零时,所求的哈密顿量能级差的解与非耦合谐振子能谱能级差的解相似,从而验证了求解结果的正确性;其二表明了坐标耦合系数、动量耦合系数和压缩性系数都对共同组成的谐振子系统能谱的能级差产生了影响;其三,对非耦合与坐标动量交叉耦合共同组成的谐振子系统能谱而言,坐标动量交叉耦合系数和非对易参数都没有对交叉耦合谐振子的能级差产生任何影响.对多种耦合系统谐振子能谱进行求解,覆盖面广,分析全面.     

在两个耦合的量子点和腔QED系统中的双模激子的压缩性质(英文)

本文研究了在两个耦合的量子点和腔QED系统中的双模激子的压缩性质.讨论了不同的初始光场对双模激子的正常压缩与和压缩的影响.计算表明,当初始态光场制备在相干态时,双模激子既不存在正常压缩,也不存在和压缩,这说明双模激子振辐的两个正交分量具有相同的量子涨落;然而,当初始腔场处于压缩真空态时,无论是正常压缩还是和压缩,双模激子振辐的两个正交分量总有一个存在压缩.这意味着量子噪声能被有效的得到抑制.此外,两种情形下的最大压缩都由初始腔场的压缩因子r决定.经过比较,我们还发现双模激子的正常压缩比和压缩大.     

三种方法求解外场驱动含时谐振子系统的异同

讨论了外场驱动含量谐振子系统的三种解法的异同，发现利用相干态平均方法与量子不变量理论所得结果一致，而利用海森伯运动方程所求结果与上述两种结果相关一个相位因子。     

二次型含时间的谐振子系统的压缩态和压缩相干态

利用演化算符方法研究了最一般的二次型含时间的谐振子系统的时间演化和压缩态问题,进一步讨论了脉动质量的受迫谐振子系统的压缩态和高n压缩态.最后,构造了在时间演化过程中保持最小测不准关系的压缩相干态和高n压缩相干态. 关键词：     

Kerr介质中双模纠缠相干光与Bell态原子相互作用系统的原子偶极压缩

运用全量子理论并结合数值计算方法，研究了Kerr介质腔中处于Bell态的两个全同二能级纠缠原子与双模纠缠相干光场相互作用系统的原子偶极压缩特性.讨论了双原子体系的初态、光场的平均光子数、双模纠缠相干光场的纠缠程度以及Kerr介质与双模光场的耦合强度对原子偶极压缩特性的影响.结果表明：双原子体系的初态为|β₁₁>时，不会出现偶极压缩效应；初态为|β₀₀>，|β₀₁>或|β₁₀>时在一定条件下可能出现原子压缩效应，且此时原子压缩的特性与Kerr介质与双模光场的耦合强度、初始光场的平均光子数、双模纠缠相干光场的纠缠程度有关. 关键词： 量子光学 Bell态 双模纠缠相干光场 Kerr介质     

Evolution and Generation of Dynamics of Two-Mode Squeezed States of Time-Dependent Coupled Boson System

The system of the Hamiltonian involving a driving part, a single mode part, and a two-mode squeezed one and a two-mode coupled one is discussed using the Lewis-Riesenfeld invariant theory. The time evolution operator is obtained. When the initial state is a coherent state, the quantum fluctuation of the system is calculated, and it is dependent on the squeezed part and the two-mode coupled part, but not dependent on the driving one.     

Time Evolution and Squeezing of Degenerate and Non-degenerate Coupled Parametric Down-Conversion with Driving Term

By properly selecting the time-dependent unitary transformation for the linear combination of the number operators, we construct a time-dependent invariant and derive the corresponding auxiliary equations for the degenerate and non-degenerate coupled parametric down-conversion system with driving term. By means of this invariant and the Lewis-Riesenfeld quantum invariant theory, we obtain closed formulae of the quantum state and the evolution operator of the system. We show that the time evolution of the quantum system directly leads to production of various generalized one- and two-mode combination squeezed states, and the squeezed effect is independent of the driving term of the Hamiltonian. In somespecial cases, the current solution can reduce to the results of the previous works.     

Parametric oscillation with the cavity mode driven by coherent light and coupled to a squeezed vacuum reservoir

We seek to investigate, employing stochastic differential equations, the squeezing and statistical properties of the cavity mode of a degenerate parametric oscillator driven by coherent light and coupled to a squeezed vacuum reservoir. Contrary to the case of the squeezed vacuum reservoir, it is found that the driving coherent light has no effect on the squeezing properties of the cavity mode. However, both the squeezed vacuum reservoir and the driving coherent light increase the mean photon number of the cavity mode.     

Squeezed states of light as self-similar structures

A new approach to investigating a broad class of dynamic states for a quantum oscillator is suggested. It is based on an invariant transformation of the equation to a new time determined by the quantum dispersion of the corresponding state. The squeezed states of a quantum system generated by the ground-state wave function are constructed. In coordinate representation, these states are described by a self-similar wave function localized near a classical trajectory. The statistics of the squeezed state of light is analyzed in the single-mode approximation. The parametric excitation of squeezed states for a quantum harmonic oscillator is considered.     

Photon Statistics of the Micromaser with Ultre Cold Λ-Type Three-Level Atoms

Coupled squeezed states for the Landau system (planar charged particle moving in a uniform magnetic field)are built.These coupled squeezed states adn decoupled squeezed Landau states give some information about the circjlar motion of charged particles resprctively.     

耦合压缩Landau态

引入Landau体系（带电粒子在垂直于均匀磁场平面内的运动）的耦合压缩态．这类耦合压缩态所给出的关于带电粒子圆周运动的信息与非耦合压缩Landau态所给出的信息存在很大的差异． 关键词：     

Squeezed states in the Jaynes-Cummings model

It is shown that squeezed states of the electromagnetic field are obtained in the Jaynes-Cummings model of an atomic transition coupled to a single mode, quantized electromagnetic field.     

Squeezing Effect of the Charge and Current in Mesoscopic Coupled Circuit with Alternating Source

We study the dynamic evolution of a mesoscopic coupled circuit with alternating source and solve its time-dependent Schrödinger equation with the help of the time dependent invariant of the Hermitian operator. It indicates that the state of the system can evolve a generalized squeezed state. The results show that in certain circumstance, compared to the initial vacuum state, either the charges or the currents in two meshes are squeezed simultaneously in the same extent. The expression of the nonadiabatic geometric phase in the circuit is also obtained.