Deterministic and exact entanglement teleportation viathe W state

Utilizing a three-particle W state, we come up with a protocol for the teleportation of an unknown two-particle entangled state. It is shown that the teleportation can be deterministically and exactly realized. Moreover, two-particle entanglement teleportation is generalized to a system consisting of many particles via a three-particle W state and a multi-particle W state, respectively. All unitary transformations performed by the receiver are given in a concise formula.     

关于一个组合常数的注记

本文证明了下面定理．设Ｇ是一个有限Ａｂｅｌ群，ｅ为Ｇ的元之最大阶，则对任一由Ｇ的元构成｜Ｇ｜＋ｅ－１项序列都可找到其中ｅ项和为０.     

Steganalysis and improvement of a quantum steganography protocol via a GHZ4 state

Quantum steganography that utilizes the quantum mechanical effect to achieve the purpose of information hiding is a popular topic of quantum information. Recently, E1 Allati et al. proposed a new quantum steganography using the GHZ4 state. Since all of the 8 groups of unitary transformations used in the secret message encoding rule change the GHZ4 state into 6 instead of 8 different quantum states when the global phase is not considered, we point out that a 2-bit instead of a 3-bit secret message can be encoded by one group of the given unitary transformations. To encode a 3-bit secret message by performing a group of unitary transformations on the GHZ4 state, we give another 8 groups of unitary transformations that can change the GHZ4 state into 8 different quantum states. Due to the symmetry of the GHZ4 state, all the possible 16 groups of unitary transformations change the GHZ4 state into 8 different quantum states, so the improved protocol achieves a high efficiency.     

群的融合自由积的几种广义Fratttini子群

M.K.Azarian将C.Y.Tang的一个引理推广到了下拟Frattini子群的情况,并且还提出了两个公开问题.为了回答这两个问题,进一步研究了群的融合自由积的一些广义Frattini子群,并且得到了一些结果.     

Attack on the Enhanced Multiparty Quantum Secret Sharing

Recently, Gao et al.'s [Commun. Theor. Phys. 52 (2009) 421] multiparty quantum secret sharing (MQSS) protocol with two-photon three-dimensional Bell states was enhanced by Hwang et al. [Commun. Theor. Phys. 56 (2011) 79]. The improved protocol removes some unnecessary unitary operations, devices, and transmissions by the technique of decoy single photons and careful modification. However, in this paper, we investigate the security of the improved protocol and find it is insecure. The eavesdropper can steal all Alice's secret information. Furthermore, a feasible modification to remedy the security loophole is put forward. Our improved protocol provides a basic method to modify a kind of MQSS protocols which cannot resist the collusion attack.     

四维二阶 Hadamard 矩阵的分类

一、引言所谓 n 维 m 阶 m~n Hadamard 矩阵(简称为 H 阵)就是满足下面两个条件的 n 维矩阵A=[A_(ij…z)]。条件1:A_(ij…z)=±1(0≤i,j,…,z≤m-1),其中 A_(ij…z)的下标有n 个。条件2:sum from p sum from q…sum from y A_(pq…ya)A_(pq…yb)=m~(n-1)δ_(ab)(这里(Pq…yn),是(ij…z)的任意一个置换,δ_(ab)=(?)容易看出当 n=2时,它就是以前大家所熟知的Hadamard 矩阵。关于高维 Hadamrd 矩阵的细节可见[1]。     

混沌蚂蚁群算法设计T-S模糊系统

介绍了混沌蚂蚁群算法，然后利用该算法设计T-S模糊系统，给出了具体的设计过程，并成功地将其应用于非线性动态系统辨识和自适应模糊控制，最后给出了数值仿真，数值仿真表明该方法是有效的.     

节点含时滞的不确定复杂网络的自适应同步研究

研究了节点带有时滞,网络结构已知或者完全未知时的不确定动态网络模型的同步问题.基于李雅普诺夫稳定性理论,并按照参数的已知和未知情况分别设计了复杂网络同步控制器和复杂网络同步自适应控制器,给出了网络同步的充分条件,保证了动态网络渐进同步于任意指定的网络中的单独节点的状态.最后,数值结果表明了方法的有效性. 关键词： 自适应同步 不确定复杂网络 Lyapunov稳定理论     

Quantum Message Distribution

The semiquantum techniques have been explored recently to bridge the classical communications and the quantum communications.In this paper,we present one scheme to distribute the messages from one quantum participate to one weak quantum participate who can only measure the quantum states.It is proved to be robust by combining the classical coding encryption,quantum coding and other quantum techniques.     

AMSAA-BISE可靠性增长模型不能成立

阐述周源泉、翁朝曦提出的AMSAA-BISE模型存在的问题,提出一个近似计算模型,并给出数值例加以说明.