一种新颖结构的高温超导信道滤波器设计

文章提出了一种新颖结构的高温超导信道滤波器设计方法,采用Sonnet软件进行微带电路的全波电磁场仿真.设计了一个一分二的高温超导信道滤波器,信道滤波器工作在S波段,每个信道的相对带宽约为0.4‰,采用的材料为多源热共蒸发法制备的DyBCO双面超导薄膜,衬底为0.5mm厚度的氧化镁.本文给出了本信道滤波器的等效电路、理论曲线、耦合参数和模拟仿真结果.     

一维抛物势场中单电子量子比特的性质

根据-维抛物势场中单电子能量本征波函数的特点,以基态和第二激发态波函数构造一个量子比特,并研究量子比特的性质.数值计算表明,量子比特内电子的概率密度随空间坐标和时间的变化而变化,在平衡位置概率密度幅值最大,在其他位置相对较小;且各个空间点的概率密度均随时间做周期性振荡,振荡周期完全由抛物势场的性质决定.     

利用N粒子纠缠态的量子秘密共享

为了高效实现多方之间的量子秘密共享,引入了一种纠缠度较高的N粒子纠缠态,并提出了利用该N粒子纠缠态在一方与(N-1)方之间形成共享秘密位串的方案.该方案在建立秘密位串的过程中,Alice对发送的粒子随机选择么正操作I和σx,并选择一部分粒子用于检测信道的安全;之后Alice根据(N-1)方选择的操作又选择了一部分粒子用于对参与者诚实度检测及信道安全检测.通过多次对窃听者的检测,很好地保证了信道的安全性及产生的秘密位串的可用性.最终在Alice及另外(N-1)方之间可形成n[1-(N-1)/2N-1]/6个共享秘密位.     

An Efficient Scheme for Multiparty Multi-particle State Sharing

We present an efficient scheme for sharing an arbitrary m-qubit state with n agents. In our scheme, the sender Alice first shares m Bell states with the agent Bob, who is designated to recover the original m-qubit state. Furthermore, Alice introduces n- 1 auxiliary particles in the initial state ｜0）, applies Hadamard （H） gate and Controlled-Not （CNOT） gate operations on the particles, which make them entangled with one of m particle pairs in Bell states, and then sends them to the controllers （i.e., other n - 1 agents）, where each controller only holds one particle in hand. After Alice performing m Bell-basis measurements and each controller a single-particle measurement, the recover Bob can obtain the original unknown quantum state by applying the corresponding local unitary operations on his particles. Its intrinsic efficiency for qubits approaches 100%, and the total efficiency really approaches the maximal value.     

Entanglement for Two-Qubit Extended Werner-Like States： Effect of Non-Markovian Environments

We investigate the sudden birth and sudden death of entanglement of two qubits interacting with uncorrelated structured reservoirs. The system is initially prepared in two-qubit extended Werner-like state. We work out the dependence of the entanglement dynamics on both non-Markovian environments and the purity of initial state, and show that non-Markovian environments and the purity can control the time of the two-qubit entanglement sudden death and the reservoirs＇ entanglement sudden birth. Furthermore, under the conditions of different purity and initial entangIement, the revival of qubits＇ entanglement can manifest before, simultaneously or even after the disentanglement of their corresponding reservoirs.     

Unconventional Geometric Quantum Gate in Circuit QED

We propose a scheme to implement an unconventional geometric phase gate in circuit QED, i.e. two superconducting charge qubits inside a superconducting transmission line resonator. The quantum operation depends only on global geometric features, and thus is insensitive to the state of the cavity mode.     

Bidirectional Mapping between a Biphoton Polarization State and a Single-Photon Two-Qubit State

How to manipulate （operate or measure） single photons efficiently and simply is the basic problem in optical quantum information processing. We first present an efficient scheme to transform a biphoton polarization state to a corresponding single-photon state encoded by its polarization and spatial modes. This single-photon state carries both the information of the controlled and target photons. It will make the realization of bipartite positive- operator-valued measurements efficiently and simply. Moreover, the inverse transformation from the single-photon state back to the corresponding biphoton polarization state is also proposed. Using both the transformations, the realization of the arbitrary two-qubit unitary operation is simple with an M-Z interferometer. All the schemes are feasible with the current experimental technology.     

Schemes for Teleportation of an Unknown Single-Qubit Quantum State by Using an Arbitrary High-Dimensional Entangled State

We propose a scheme to teleport an unknown single-qubit state by using a high-dimensional entangled state as the quantum channel. As a special case, a scheme for teleportation of an unknown single-qubit state via three-dimensional entangled state is investigated in detail. Also, this scheme can be directly generalized to an unknown f-dimensional state by using a d-dimensional entangled state （d〉f） as the quantum channel.     

相位阻尼信道条件下量子斗鸡博弈模型均衡解分析

利用量子博弈的相关理论,以噪音强度和记忆强度为参量,建立了相位阻尼信道条件下的量子斗鸡博弈模型,求出了模型的量子纳什均衡解,讨论了两参量对均衡解稳定性的影响,得出在无记忆相位阻尼信道条件下,当噪音强度小于阈值0.24时,纳什均衡仍然为帕累托最优解,当噪音强度大于0.24时,均衡解演变为另2个均衡解,不再是帕累托最优;在有记忆相位阻尼信道条件下,当噪音强度小于0.24,且记忆强度大于0.5时,均衡解是稳定的.特殊地,当信道是完全记忆时,均衡解的稳定性与噪音强度无关.     

关于合成矩阵的几个性质

利用合成矩阵的概念和翻转矩阵的技巧,结合矩阵的次转置、次自共轭,中心对称等相关情况给出合成矩阵的几个性质,并获得关于n阶翻转矩阵的第n-1个合成矩阵的表达式.