Entanglement sudden death of two atoms interacting with a cavity via the two-photon process in a strong-driving-assisted system

We examine the entanglement dynamics between two strongly driven atoms off-resonantly coupled with a single-mode cavity via the two-photon process with the help of negativity in two different types of initial states. The results show that entanglement sudden death may occur under both the above conditions and the sudden death effect can be monitored by modulating the atom--cavity detunings. Furthermore, we also find an atomic decoherence-free subspace so that the initial entanglement between two atoms remains invariable in application.     

交叉积的同调维数

本文证明了当Ｈ是有限维半单和余半单的Ｈｏｐｆ代数时,Ｒ与交叉积Ｒ＃σＨ的整体维数是相同的;同时,它们的弱维数也是相同的．     

Quantum secure direct communication protocol with blind polarization bases and particles＇ transmitting order

This paper presents a modified secure direct communication protocol by using the blind polarization bases and particles' random transmitting order. In our protocol, a sender (Alice) encodes secret messages by rotating a random polarization angle of particle and then the receiver (Bob) sends back these particles as a random sequence. This ensures the security of communication.     

在Skyrme模型中关于解析质量计算的研究

本文用Reduce语言^[1]研究了Skyrme模型^[2、3、4]中孤立子质量的计算方法。上机计算结果表明,矩阵方法和具体展开方法比一般算符表达式更为优越。     

依赖于时间和强度耦合Jaynes-Cummings模型中原子的量子特性

本文研究了依赖于时间和强度耦合Jaynes-Cummings模型中原子的动力学行为.详细讨论了脉冲宽度和腔场强度对原子能级布居数反转的影响.     

有源RLC介观电路的量子涨落

使用正则交换和幺正变换的方法，研究了有源RLC介观电路的量子涨落。结果表明电源电动势ε(t)的有无对电荷和电流的量子涨落没有影响。     

二粒子纠缠态受控传递的最佳量子通道

本文研究了如何在二粒子纠缠态的量子受控传递中选择最佳量子通道的问题。分别利用四粒子GHZ态和四粒子特殊"反关联GHZ态"作为量子通道,本文提出了二粒子反关联纠缠态的量子受控传递的两个方案。通过对比两个方案下接受者最后采取的幺正操作的具体矩阵形式,分析了待传量子纠缠态与量子通道的关系,指出了四粒子GHZ态和四粒子特殊"反关联GHZ态"分别是二粒子正关联和反关联纠缠态各自隐形传递应该选择的最佳的量子通道。     

反Tavis-Cummings模型中纠缠原子布居的时间演化

利用反Tavis-Cummings模型研究了初始处于纠缠态的两个全同二能级原子与单模二项式光场的相互作用.在强经典驱动和大失谐的情况下,原子与光场的相互作用可以转化为有效的Tavis-Cummings模型和反Tavis-Cummings模型.主要是研究了反Tavis-Cummings模型下纠缠原子布居的时间演化.结果表明,纠缠原子布居的时间演化和光场的强度以及光场的初始状态有关.     

Generating a four-photon polarization-entangled cluster state with homodyne measurement via cross-Kerr nonlinearity

We propose a protocol to generate a four-photon polarization-entangled cluster state with cross-Kerr nonlinearity by using the interference of polarized photons. The protocol is based on optical elements, cross-Kerr nonlinearity, and homodyne measurement, therefore it is feasible with current experimental technology. The success probability of our protocol is optimal, this property makes our protocol more efficient than others in the applications of quantum communication.     

Skyrme模型中新的附加质量项对重子及其共振态的影响

本文研究了由于对Skyrme模型的拉氏量进行量子力学处理后产生的新的附加质量对重子及其共振态的影响.