Minimax Strategy of Optimal Unambiguous State Discrimination

In this paper, we consider the minimax strategy to unambiguously discriminate two pure nonorthogonal quantum states without knowing a priori probability. By exploiting the positive-operator valued measure, we derive the upper bound of the minimax measurement of the optimal unambiguous state discrimination. Based on the linear optical devices, we propose an experimentally feasible scheme to implement a minimax measure of a general pair of two nonorthogonal quantum states.     

W类态三纠缠原子与相干态光场相互作用过程中光场的量子特性

研究了处于W类态的三纠缠原子与相干态光场相互作用过程中光场的量子特性;运用数值方法,讨论了三纠缠原子初始状态和相干态光场的强弱对系统光场压缩和二阶相干特性的影响。     

两纠缠原子与二项式光场相互作用的动力学

采用时间演化算符和数值计算方法，研究了两全同二能级纠缠原子与二项式光场相互作用的动力学，结果表明原子布居和原子偶极压缩的时间演化与二项式光场系数和两纠缠原子的纠缠度有很强的关联，选择合适的系统参数，原子偶极矩可以被完全压缩. 关键词： 纠缠原子 二项式态 原子布居 偶极压缩     

双模纠缠相干光场与V型三能级原子相互作用系统的光子统计性质

本文采用求解Schrodinger方程和数值计算方法,研究了双模纠缠相干光场与三能级原子相互作用系统的光子统计性质,结果表明:此性质与双模纠缠相干光场的纠缠程度、失谐量、双模光的平均光子数和原子的初态相关联.     

Generation of various multiatom entangled graph states via resonant interactions

In this paper, a scheme for generating various multiatom entangled graph states via resonant interactions is proposed. We investigate the generation of various four-atom graph states first in the ideal case and then in the case in which the cavity decay and atomic spontaneous emission are taken into consideration in the process of interaction. More importantly, we improve the possible distortion of the graph states coming from cavity decay and atomic spontaneous emission by performing appropriate unitary transforms on atoms. The generation of multiatom entangled graph states is very important for constructing quantum one-way computer in a fault-tolerant manner. The resonant interaction time is very short, which is important in the sense of decoherence. Our scheme is easy and feasible within the reach of current experimental technology.     

压缩真空场与运动型三能级原子作用系统的光场压缩效应

采用求解Schr dinger方程和数值计算方法,研究了单模压缩真空场与运动Ξ型三能级原子相互作用过程中系统的动力学行为,讨论了系统参数对系统光场压缩效应的影响.数值计算结果表明:原子运动速度的大小决定了光场的压缩性质,当原子运动速度取较大值时,单模压缩真空场的初始压缩因子变化对光场的压缩性质产生明显影响.如选取适当的系统参数,就会产生完全压缩的光场.     

两纠缠原子与光场相互作用系统场熵演化特性

研究了两纠缠原子与相干态光场相互作用系统场熵的时间演化特性,运用全量子力学理论和数值方法,讨论了初始两原子所处的纠缠状态、纠缠度和腔内光场的强弱对场熵的影响.     

微波场驱动三能级原子系统的自感应透明现象

讨论光微波场驱动的三能级原子系统与光脉冲相互作用的动力学过程,推导出光学面积定理,并研究自感应透明现象,发现在特殊条件下该体系的某些性质与二能级原子体系一样。 关键词：     

两纠缠原子与相干态光场相互作用过程中光场的量子特性

采用时间演化算符和数值计算方法,研究了两全同二能级纠缠原子与相干态光场相互作用过程中光场的量子特性,结果表明:两原子初始纠缠度和相干态光场强度对系统光场的二阶相干性质和压缩效应有很大的影响.     

Entanglement Evolution of a Two-Qubit System beyond Rotating-Wave Approximation

Two noninteracting qubits, initially entangled in Bell states, are coupled to a one-mode cavity and evolve under its influence. The entanglement evolution of the two qubits is investigated beyond the rotating-wave approximation. It is shown that the counter-rotating wave terms have a great influence on the disentanglement behavior.