Double-wave description of mesoscopic resistance-inductance-capacitance coupled circuit with power source

Quantum fluctuations in the mesoscopic capacitance-inductance-resistance coupled circuit with a power source are investigated using canonical transformation and a double wavefunction. We confirm that the fluctuations are not influenced by the power source. As a new method, the double wavefunction describes a single system of the coupled circuit, whereas the single wavefunction describes a quantum ensemble.     

通过幺正操作传送未知两个三能级粒子纠缠态

我们提出一个把未知的两个三能级粒子纠缠态传送给两个接收者的方案,该方案使用一个未知的五个三能级粒子纠缠态作为量子通道。必须指出该方案能够推广到传送未知的N个三能级粒子纠缠态给M个接收者的情况,使用的是未知(N.M 1)个三能级粒子纠缠态作为量子通道。在传送过程中,需要执行适当的幺正操作和(N.M 1)次独立测量,而且该方案不涉及Bell态测量。     

余模分解与余代数分解的关系

设M是C-余模,C和M分别能被分解成不可分的子余代数和子余模的直和.给出这两个分解式之间的关系,从而给出了C的可约性和可分性与M的相关可约性和可分性之间的关系.     

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.     

依赖于时间和强度耦合J-C模型中原子偶极压缩特性

研究了依赖于时间和强度耦合J-C模型中原子的偶极压缩现象。并详细讨论了原子与腔场以时间脉冲形式耦合时,脉冲宽度和腔场强度对原子算符压缩的影响。结果表明,在此模型下原子的偶极压缩随时间的演化特性与其他强度耦合模型明显不同,而且可以通过调节脉冲宽度有效控制原子的偶极压缩程度。     

Generation of a χ-type four-atom entangled state

This paper proposes a scheme to generate a new χ-type four-atom entangled state for the first time by using linear optics elements, four one-sided cavities (one three-level atom) and a conventional photon detector. The linear optical elements and conventional photon detector are simple and accessible in experiments, which makes the scheme more feasible with current technology. In addition, the state |χ⁰⁰₃₂₁₄ with probability 1 can be generated as long as there is no photon loss.     

Deterministic implementations of fermionic quantum SWAP and Fredkin gates for spin qubits based on charge detection

We propose a scheme to implement fermionic quantum SWAP and Fredkin gates for spin qubits with the aid of charge detection. The scheme is deterministic without the need of qubit–qubit interaction, and the proposed setups consist of simple polarizing beam splitters, single-spin rotations, and charge detectors. Compared with linear optics quantum computation, this charge-measurement-based qubit scheme greatly enhances the success probability for im- plementing quantum SWAP and Fredkin gates and greatly simplifies the experimental realization of scalable quantum computers with noninteracting electrons.     

Nonlocal quantum cloning via quantum dots trapped in distant cavities

A scheme for implementing nonlocal quantum cloning via quantum dots trapped in cavities is proposed.By modulating the parameters of the system,the optimal 1 → 2 universal quantum cloning machine,1 → 2 phase-covariant cloning machine,and 1 → 3 economical phase-covariant cloning machine are constructed.The present scheme,which is attainable with current technology,saves two qubits compared with previous cloning machines.     

广义路代数与点Hopf代数

Most of pointed Hopf algebras of dimension p^m with large coradtical are shown to be generalized path algebras. By the theory of generalized path algebras, the representations, homological dimensions and radicals of these Hopf algebras are obtained. The relations between the radicals of path algebras and connectivity of directed graphs are given.     

Change-over switch for quantum states transfer with topological channels in a circuit-QED lattice

We propose schemes to realize robust quantum states transfer between distant resonators using the topological edge states of a one-dimensional circuit quantum electrodynamics(QED)lattice.Analyses show that the distribution of edge states can be regulated accordingly with the on-site defects added on the resonators.And we can achieve different types of quantum state transfer without adjusting the number of lattices.Numerical simulations demonstrate that the on-site defects can be used as a change-over switch for high-fidelity single-qubit and two-qubit quantum states transfer.This work provides a viable prospect for flexible quantum state transfer in solid-state topological quantum system.