用偏振缠绕的光子对进行量子通讯和密集编码

研究如何利用两粒子形成的ＥＰＲ－Ｂｅｌｌ态传输光子的量子态，并提出依赖于两光子缠绕的密集编码实验设想。     

两能级原子与辐射的相互作用

本文研究两个两能级原子与辐射的相互作用．在不同的初始条件下，得到了原子处于高能态的几率以及辐射场中的光子数随时间的变化规律．     

用基本的两位量子门构造Fredkin门

本文在Ａ Ｂａｒｅｎｃｏ的工作基础上，提出了用基本的两位量子门实验Ｆｒｅｄｋｉｎ门的功能。与Ｈ Ｆ ＣＨｈａｕ的方案相比较，该方案具有结构简单，地理解和实现的特点。     

能级间同时存在衰变和跃迁时的消相干特性

二能级原子在量子信息中可视为量子位.本文基于约化密度矩阵理论,利用量子纯态和混合态分析方法,针对二能级原子能级间同时存在衰变和跃迁的情况,研究原子消相干特性.     

左手介质中电磁波的传播速度

在同向介质中,电磁波的群速度一般是能量传播的方向,并且电磁波的相速度和群速度在大部分情况下都满足瑞利关系.为了研究左手介质的电磁特性,本文从理论上导出了左手介质中电磁波的相速度、群速度及其关系,得出左手介质中电磁波的群速度为负,并介绍了左手介质的一些应用前景.     

含Dzyaloshinski-Moriya相互作用的三量子位HeisenbergXX链的热纠缠

研究了外加磁场下具有Dzyaloshinski-Moriya(DM)各向异性反对称相互作用的三量子位Heisenberg XX链的对热纠缠以及在热平衡下用该链作为信道来传输未知的量子态。详细地给出了磁场、DM相互作用及温度对热纠缠和平均传输保真度的影响。结果表明:磁场和DM相互作用可以有效地调控对热纠缠;在温度较低情况下,关闭磁场和DM相互作用,顺铁磁链可以很好地用来做隐形传态的信道;纠缠不能完全反映平均传输保真度,相同的纠缠可以导致不同的平均传输保真度。     

Simple schemes for generation of W-type multipartite entangled states and realization of quantum- information concentration

We propose simple schemes for generating W-type multipartite entangled states in cavity quantum electrodynamics (CQED). Our schemes involve a largely detuned interaction of Λ-type three-level atoms with a single-mode cavity field and a classical laser, and both the symmetric and asymmetric W states can be created in a single step. Our schemes are insensitive to both the cavity decay and atomic spontaneous emission. With the above system, we also propose a scheme for realizing quantum-information concentration which is the reverse process of quantum cloning. In this scheme, quantum-information originally coming from a single qubit, but now distributed into many qubits, is concentrated back to a single qubit in only one step.     

LASER-CONTROLLED STATE EXCITATION AND QUANTUM COMPUTATION

Based on the dependence of the molecular excitation probabilities on the laser phases and amplitudes in the model of a three-mode laser interacting with a three-level molecule, we propose a scheme to implement quantum XOR logic gate and to construct quantum error prevention code.     

消除热库中量子位的消相干性

以二能级原子作为量子位,利用求解相互作用系统约化密度矩阵非对角元的方法,分别研究热库中量子位模型和依赖强度耦合Jaynes-Cummings模型的消相干特性.当外加驱动场消除消相干时,得到两种模型下驱动场必须满足的约束方程.?     

Superposed Transparency Effect and Entanglement Generation with Hybrid System of Photonic Molecule and Dipole Emitter

We theoretically investigate the transparency effect with a hybrid system composed of a photonic molecule and dipole emitter. It is shown that the transparency effect incorporates both the coupled resonator-induced transparency(CRIT) effect and the dipole-induced transparency(DIT) effect. It is found that the superposed transparency windows are consistently narrower than the CRIT and DIT transparency windows. Benefiting from the superposed transparency effect, the photonic Faraday rotation effect could be realized in the photonic molecule system, which is useful for entanglement generation and quantum information processing.