Teleportation of n-Particle State via n Pairs of EPR Channels

The teleportation of an arbitrary n-particle state is proposed if n pairs of identical EPR states are utilized as quantum channels. Independent Bell state measurements are performed for joint measurement. By using a special Latin square of order , explicit expressions of outcomes after the Bell state measurements by Alice (sender) and the corresponding unitary transformations by Bob (receiver) can be derived. It is shown that the teleportation of n-particle state can be implemented by a series of single-qubit teleportation.

Probabilistic Teleportation of n-Particle State via n Pairs of Entangled Particles

The teleportation of an arbitrary n-particle state is proposed when n pairs of entangled particles are utilized as quantum channels. It can be successfully realized with a certain probability which is determined by the smallest coefficients of n entangled pairs. Using a Latin square of order 2n, explicit expressions of two unitary operations corresponding to different Bell-basis measurements performed by Alice can be obtained at the end of Bob.

A new representation and probabilistic teleportation of an arbitrary and unknown N-particle state

A new representation of an arbitrary and unknown N-particle state is presented at first. As an application, a scheme for teleporting an arbitrary and unknown N-particle state is proposed when N pairs of two-particle non- maximally entangled states are utilized as quantum channels. After Alice （sender） makes Bell-state measurement on her particles, Bob （recipient） introduces an auxiliary particle and carries out appropriate unitary transformation on his particle and the auxiliary particle depending on classical information from Alice. Then, von Neumann measurement that confirms whether the teleportation succeeds or not is performed by Bob on the auxiliary particle. In order to complete the teleportation, another N-1 times operations need to be performed which are similar to the above ones. It can be successfully realized with a certain probability which is determined by the product of the smaller coefficients of non-maximally entangled pairs. All possible unitary transformations are given in detail.

N-particles intermediate coordinate-momentum representation and its application

This paper constructs the new common eigenvectors of n intermediate coordinate-momentum operators which are complete and orthonormal. The intermediate coordinate-momentum representation of a multi-particles system is proposed and applied to a generaln-mode quantum harmonic oscillators system with coordinate-momentum coupling.

Teleportation of N-Particle Entangled GHZ State via Entanglement Swapping

In this scheme, N non-maximally entangled particle pairs are used as quantum channel to teleport an unknown N-particle entangled GHZ state via entanglement swapping. In order to realize this teleportation, the sender Alice operates Bell-state measurement on particles belonging to herself. Then she informs the results to the receiver Bob through classical communication. According to the results, Bob operates corresponding transformation to reconstruct the initial state. The advantage of this scheme is that it needs only one common unitary matrix for Alice＇s different results, which has a more general meaning. As a special case, teleporting an unknown three-particle entangled GHZ state is proposed.

Scheme for probabilistic remotely preparing a multi-particle entangled GHZ state

This paper presents a scheme for probabilistic remote preparation of a three-particle entangled Greenberger-Horne-Zeilinger （GHZ） state via three-particle orthonormal basis projective measurement, and then directly generalize the scheme to multi-particle case. It is shown that by using N pairs of bipartite non-maximally entangled states as the quantum channel and N-particle orthonormal basis projective measurement, the multi-particle remote preparation can be successfully realized with a certain probability.

Feasibility of using recycled CRT funnel glass as partial replacement of high density magnetite sand in radiation shielding concrete

The recycled cathode ray tube(CRT)funnel glass was used as replacement of magnetite sand in the concrete,and its mass replacement rates were 0,20%,40%and 60%,respectively.The flowability,apparent density and mechanical properties of the radiation shielding concrete were investigated,while itsγ-ray radiation shielding parameters such as linear and mass attenuation coefficients(μandμm,respectively),thickness values of half-value layer(hHVL)and tenth-value layer(hTVL)were obtained by theoretical calculation,experiment and Monte.Carlo N-Particle(MCNP)simulation code.The experimental results show that the flowability of the concrete increases significantly,whilst its apparent density,compressive strength and static elastic modulus decrease slightly.The calculated,simulated and experimentalμm,μ,hHVL and hTVL values of all concrete samples are very consistent at the sameγ-ray photon energy,and it is feasible to use MCNP code to simulateγ-ray radiation shielding parameters of materials.The calculated results show that in a wide range ofγ-ray photon energy,theμm value of the concrete with CRT funnel glass replacing magnetite sand is improved effectively,and its radiation shielding performances are the same as those of the control concrete(M.1).By comprehensively comparing the flowability,mechanical properties andγ-ray radiation shielding properties,the concrete samples with 20%.40%funnel glass as fine aggregate have good performances.

Teleportation of an Arbitrary Multipartite GHZ-Class State by One EPR Pair

We present a scheme for perfectly teleporting an arbitrary and unknown N-particle GHZ-class state from a sender to a receiver. We just need one quantum channel composed of two or three particles in the maximally entangled state. The sender performs one Bell-state measurement on two of her particles and N - 1 Hadamard operations and N - 1 yon Neumann measurements on the rest N - 1 particles. The receiver adopts one corresponding unitary transformation on his particles shared with the sender. After that, the receiver can obtain the original N-particle GHZ-class state by introducing N - 1 ancillary particles and carrying out N - 1 controlled-NOT operations. We also generalize the scheme to the case of controlled teleportation.

First application of large reactivity measurement through rod drop based on three-dimensional space–time dynamics

Abstract Reactivity measurement is an essential part of a zero-power physics test,which is critical to reactor design and development.The rod drop experimental technique is used to measure the control rod worth in a zero-power physics test.The conventional rod drop experimental technique is limited by the spatial effect and the difference between the calculated static reactivity and measured dynamic reactivity;thus,the method must be improved.In this study,a modified rod drop experimental technique that constrains the detector neutron flux shape function based on three-dimensional space–time dynamics to reduce the reactivity perturbation and a new method for calculating the detector neutron flux shape function are proposed.Correction factors were determined using Monte Carlo N-particle transport code and transient analysis code for a pressurized water reactor at the Ulsan National Institute of Science and Technology and Xi’an Jiaotong University,and a large reactivity of over 2000 pcm was measured using the modified technique.This research evaluated the modified technique accuracy,studied the influence of the correction factors on the modification,and investigated the effect of constraining the shape function on the reactivity perturbation reduction caused by the difference between the calculated neutron flux and true value,using the new method to calculate the shape function of the detector neutron flux and avoiding the neutron detector response function(weighting factor)calculation.

N—Particle Entangled States of Continuum Variables

We construct the n-particle entangled states |β>θ in n-mode Fock space, and examine their completeness relation and partly non-orthonormal property. Their Schmidt decomposition and entangled operator are manifestly shown. Finally, we discuss their application.

Entanglement Criterion of N-Qubit State

In this paper, we shall develop a generic scheme to construct the criterion that an N-qubit state has true N-particle entanglement. For the N = 3 case, we show that violation of the Mermin＇s inequality │ E^LHV （σ^ x× σ^ y× σ^y ＋ σ^y × σ^x×σ^y ＋ σ^y ×σ^y× σ^x＆ -σ^x × σ^x ×σ^x）│≤2, is sufficient to confirm three-particle entanglement.

MCNP可视化输入程序的开发

MCNP(Monte Carlo N-particle)输入文件格式较复杂,特别是对相关物体几何参数的描写更难,不仅书写麻烦,而且很容易出错。为方便用户准确得到输入文件,进行了MCNP可视化输入程序的开发。程序运行于Windows平台下,使用VC++和OpenGL语言编译。应用该程序,用户能够在一个三维可视化环境中创建几何体并定义区域,描写数据卡,最后直接得到符合MCNP输入文件格式要求的inp文件。

体素模型在Monte Carlo模拟计算中的描述

体素模型与Monte Carlo模拟计算方法相结合已开始应用于辐射防护的研究中。然而,通常的模拟计算需要很长的时间,这限制了体素模型的广泛应用。该文对模拟计算中体素模型的描述进行研究,实现了把三维体素合并算法用在MCNP(Monte Carlo N-particle)程序描述体素模型的方法。结果表明,使用该方法描述体素模型,粒子输运过程要比传统的方法快32%,但是对粒子在组织器官中沉积能量的纪录需要更多时间。关键词:辐射;MCNP(Monte Carlo N-particle);体素;人体模型;

次临界系统中α本征值与k本征值的关系

以Godiva临界模型为基础,建立了两种次临界模型,并计算了两种模型中不同易裂变核材料含量的k本征值和α本征值。结果表明,并非k越小,α就会越小。对于含氢介质较多的系统,即使k很小,由于瞬发中子寿命很大,α也会接近于0,因而α不能直观地表征系统的临界特性,而k比α更适合这样的系统。对瞬发中子寿命较小的次临界系统,α绝对值较大,能直观地显示系统中子随时而间的衰减行为,对这种系统,使用α是合适的。

中子时间常数的Monte Carlo计算方法

为了研究核装置内中子密度随时间的瞬态变化规律,在Monte Carlo程序DSMC(dynamic system Monte Carlo)的基础上发展了一种新的计算核装置中子时间常数方法,该方法先求得本征分布源,然后求中子时间常数。通过与MCNP(Monte Carlo N-particle)程序计算α本征值的方法及两个模型的计算结果比对分析发现:在超临界和临界情况下两者结果一致;在较深次临界情况下,新方法克服了MCNP程序方法的不足,计算结果更为可靠,特别是在MCNP4C不能顺利完成计算的情况下,新方法依然有效。

放射性粒子源近距离治疗的Monte Carlo模拟

放射性光子源如103Pd和125I已被广泛用于前列腺和眼睛的植入治疗中。本文使用MCNP4C软件计算美国医学物理学家协会(American association of physicists in medicine,AAPM)推荐的103Pd和125I的剂量学特征。由AAPM推荐的剂量学参量如剂量率常数、径向剂量函数、各项异性函数通过Monte Carlo计算得到,在材料固体水WT1(solid water)中,125I的剂量率常数为0.99,103Pd的为0.682,而在材料Water中,125I剂量率为1.01。与前研究工作者Reners的计算结果相比125I的剂量率一致,而103Pd剂量率和各向异性函数结果相差较大,这些差异是使用不同Monte Carlo代码截面数据引起的。

MCNP在惯性约束聚变核探测中的初步应用

随着惯性约束聚变的发展,对聚变产物特别是中子探测的定量分析变得非常重要。采用三维Monte Carlo输运程序MCNP(Monte Carlo N-particle),对不同铅屏蔽厚度下探测器的DT中子相对灵敏度,和中子半影成像的数值模拟进行了一定的研究。结果显示,相对灵敏度的模拟与实验结果符合得很好,而中子成像模拟能为惯性约束聚变物理实验的开展提供指导。

光子空气散射基准问题的Monte Carlo模拟

用并行化的MCNP(Monte Carlo N-particle)程序模拟了美国堪萨斯州立大学1977的光子散射实验基准问题。针对不加顶盖屏蔽层的情况,对问题的几何和材料进行了详细的描述,模拟了地面、水泥柱壳屏蔽体和小车的散射。由于问题并不是完全轴对称的,因而采用的是点探测器估计,用100个处理器模拟了1亿个样本,给出了计算结果和实验值的对比,模拟结果和试验结果存在一些差别,但趋势相同。同时,用指向概率法的MCCO程序与MCNP进行了比较。模拟中还考虑了加重要性和不加重要性对计算效率的影响。

含肿瘤BNCT网格模型的Monte Carlo剂量计算

根据Snyder解析模型建立了一个含有肿瘤的BNCT(硼中子俘获治疗)-4 mm网格模型,应用MCNP(Monte Carlo N-particle)程序进行模拟计算,并对结果进行了物理分析;使用新研制的MCDB(Monte Carlodosimetry in brain)程序对Snyder加肿瘤模型进行了模拟,得到和MCNP程序几乎完全一致的结果,验证了MCDB程序的正确性,由于MCDB采用了适合均匀网格的快速粒子径迹算法,因而提高了计算速度,较MCNP节省了36%的模拟时间。

MCNP Dose Calculations in a CT Phantom for Therapeutic External Photon Beam

In this paper,we have addressed the problem of the radiation transport with the Monte Carlo N-particle(MCNP) code.This is a general-purpose Monte Carlo tool designed to transport neutron,photon and electron in three dimensional geometries.To examine the performance of MCNP5 code in the field of external radiotherapy,we performed the modeling of an Electron Density phantom(EDP) irradiated by photons from 60Co source.The model was used to calculate the Percent Depth Dose(PDD) at different depths in an EDP.One field size for PDD has been examined.A 60Co photons source placed at 80 cm source to surface distance(SSD).The results of calculations were compared to TPS data obtained at National Institute of Oncology of Rabat.