9-量子团簇态信道的非对称双向量子信息传输

利用一个9-量子团簇态为信道,分别提出了三个关于二量子态和三量子态的双向量子信息传输协议。在第一个协议中,Alice能把三量子a1、a2和a3的未知态传送给Bob,Bob能把二量子b1和b2的未知态传送给Alice。Alice采用特殊三粒子态测量基,使得方案简化了一半。在第二个协议中,Alice在远方的Bob处制备三粒子a1、a2和a3的已知态,同时Bob也能在Alice处制备二量子b1和b2的已知态。由于他们充分利用了前馈测量策略,制备任务能够完美完成。在第三个协议中,利用前两个协议的优点,Alice能成功将三量子a1、a2和a3的未知态传送给Bob,Bob也完美地在Alice处制备二量子b1和b2的已知态。     

受控循环远程态制备

为了解决多方量子通信问题,首先提出一种构造十粒子纠缠态的方法,并籍此构造出一个3◢n◣+1粒子纠缠态。其次,以十粒子纠缠态为量子信道,提出一个三方受控循环远程制备协议。该协议在监察者David的控制下,Alice能为Bob远程制备一个任意单粒子态,Bob能够在Charlie处远程制备一个任意单粒子态,Charlie也能为Alice远程制备任意单粒子态。进一步,借助3◢n◣+1粒子纠缠态,将此循环协议推广到任意◢n◣方受控循环远程态制备情形。在远程态制备过程中,每个发送者充分利用各自掌握的信息和前馈策略来构造恰当的测量基,通过经典通信和局域操作,就能成功实现任意单粒子态的远程制备。     

任意二粒子纠缠态的受控量子通信

为了解决任意二量子通信问题,首先给出了五粒子和七粒子纠缠态的构造方法,并提供了它们的量子线路图。其次,以该五粒子纠缠态为量子信道,提出一个任意二粒子未知量子态的受控隐形传态协议。该协议在监察者Charlie的控制下,Alice进行四粒子投影测量和经典通信,Bob采用简单酉变换就能以100%的概率成功重构一个任意二粒子纠缠态。最后,利用七粒子纠缠态为量子信道,提出了任意二粒子纠缠态的联合受控远程制备方案。在此方案中,发送者Alice用自己掌握被制备态的部分信息构造测量基,发送者Bob采用前馈测量策略,接收者Diana在监控者Charlie的帮助下,通过简单幺正变换就能确定性地恢复原始态。     

以任意高维纠缠态为量子信道的受控隐形传态

目的是利用高维量子纠缠态为量子信道，讨论未知单粒子态的受控隐形传输问题。以三维量子纠缠态为信道，提出一个二维任意单粒子态的受控隐形传输协议。提出了以任意[d]-维量子纠缠态为量子信道，[t]-维任意单粒子态的隐形传输协议[(t相似文献   

传送任意三粒子纠缠态的三个方案

提出传送任意三粒子纠缠态的三个方案,分别是利用三对二粒子纠缠态、单个三粒子最大纠缠态和利用两个EPR态作为量子通道实现三粒子纠缠态的传送。通过发送者(Alice)对需传送的三粒子纠缠态与属于自己的纠缠对中的粒子分别进行适当的Bell基测量,然后把结果通过经典通道告诉接收者(Bob),接收者根据这些信息对自己拥有的三粒子进行相应的联合幺正变换,就可以实现一定概率的隐形传态。这些方案都可以推广至N个粒子纠缠态的传送。     

三维单粒子态的双向受控隐形传态

以事先分享的两个广义最大纠缠GHZ态为量子信道,提出了一个三维单粒子态双向受控隐形传态协议。在该协议中,遥远的两方可以在第三个遥远方的控制下同时、确定性地交换他们的三维单粒子态,这种交换在没有控制者的许可下是不会成功的。为了推广这一协议,采用投影测量和正算子值测量,分别提出了两个双向受控的三维单粒子态隐形传输协议。在这两个协议中,两个广义非最大纠缠GHZ态被用作量子信道来连接三个合法参与者,量子任务总能以一定的概率来完成。     

以最大slice态为信道的受控量子远程控制

利用三量子最大slice态作为量子信道,提出了单量子酉算子的受控远程执行的两个协议.首先,利用双向量子隐形传态(BQST),给出了一个任意单量子酉算子的受控隐形传输方案.结果 表明,通过非最大纠缠信道,发送者能够在遥远的接受者的量子系统上远程地执行一个任意单量子酉算子.如果发送者和控制者对各自量子执行恰当的投影测量,那...     

基于多参数测量的双向受控隐形传态

融合了双向隐形传态、受控隐形传态、概率隐形传态及多参数测量思想,提出了一个新的双向受控概率隐形传态协议。在该协议中,以五粒子非最大纠缠团簇态为信道,发送者采用多参数通用测量,接收者引入辅助粒子,并在控制者的允许下,利用测量信息施行适当酉变换,就能以一定概率同时交换他们的量子态。分析了成功概率（经典耗费）与量子纠缠参数及测量参数间的依赖关系,说明了该协议可以根据量子信道的参数来调整多参数测量的参数,达到调节成功概率或经典耗费,满足真实世界中多种不同需求的目的。此外,该协议是经典双向受控隐形传态的推广。     

两个基于四粒子纠缠态的量子秘密共享方案

本文分别基于四粒子Cluster态和一个非对称的四粒子纠缠态,提出两个量子秘密共享的方案,其中共享的秘密是未知的单粒子态。秘密的发送者需要对手中的粒子进行Bell基测量,协助者需要对手中的粒子进行测量或者实施幺正操作,最后接收者通过对手中的粒子进行相应的幺正变换或者受控非门操作,就可以重构原始秘密。通过分析表明,任何一个代理者在其他两方协助下是可以恢复秘密的,所以我所提出的方案是高效且安全可靠的。     

可控量子远程通信方案的研究

针对一般可控量子远程通信方案能防止外部窃听,但无法有效防止冒充攻击这一安全缺陷,提出一种具备身份认证功能的可控量子远程通信方案。可信任第三方Charlie利用纠缠交换对接收者Bob进行身份认证,在确定Bob的合法身份并将消息反馈给发送者Alice后,Alice再传送量子信息。该方案利用身份认证能有效防止冒充攻击,并能够增强量子信息传送的正确性和安全性。     

Three-party remote state preparation schemes based on entanglement

By exploiting the entanglement correlation in quantum mechanics, two three-party remote state preparation (RSP) schemes are proposed. One is three-party remote preparation of a single-particle quantum state, and the other is three-party remote preparation of a two-particle entangled state. In the proposed schemes, the sender Alice knows the quantum states to be prepared, while the receivers Bob and Charlie do not know the quantum states; Alice performs measurement and unitary operations on her own particles with two three-particle GHZ states as the quantum channel. According to Alice’s measurement results, Bob and Charlie measure their own particles on the corresponding quantum measurement bases and perform unitary operations on the corresponding particles to reconstruct the quantum states, respectively. Compared with multiparty joint remote preparation and two-party RSP of a quantum state, the proposed schemes realize quantum multicast communication successfully, which enables Bob and Charlie to obtain the prepared quantum states simultaneously in the case of just knowing Alice’s measurement results, while Bob and Charlie do not know each other’s prepared quantum states. It is shown that only three classical bits are required for the two proposed RSP schemes when Bob and Alice introduce an auxiliary particle, respectively, and the proposed schemes are secure after the quantum channel authentication.     

Asymmetric bidirectional controlled remote preparation of an arbitrary four-qubit cluster-type state and a single-qubit state

In this paper, we propose a novel scheme for asymmetric bidirectional controlled remote state preparation (ABCRSP) via a ten-qubit entangled state as the quantum channel. In this scheme, two distant parties, Alice and Bob are not only senders but also receivers, and Alice wants to remotely prepare a single-qubit state at Bob’s site; at the same time, Bob wishes to help Alice remotely prepare an arbitrary four-qubit cluster-type entangled state. It is shown that only if the two senders and the controller collaborate with each other, the ABCRSP can be completed successfully. We demonstrate that the total success probability of the ABCRSP in this scheme can reach 1, that is, the scheme is deterministic.     

利用纠缠态实现任意N粒子量子态的秘密共享

针对量子秘密共享的量子态局限于最大纠缠态的问题,提出一种实现任意N位量子态的秘密共享方案。该方案使用纠缠态作为量子信道,首先发送方对粒子进行Bell基测量,然后接收方Bob或Charlie使用单粒子测量,最后参与者根据Alice和单粒子测量得到的结果,选用合适的联合幺正变换对量子态进行相应的变换,这样可以实现任意N粒子量子态的秘密共享。该方案能够抵御外部窃听者和内部不诚实参与者的攻击,安全性分析表明此方案是安全的。     

Asymmetric multi-party quantum state sharing of an arbitrary m-qubit state

We present a scheme for asymmetric multi-party quantum state sharing of an arbitrary m-qubit state with n agents. The sender Alice first shares m − 1 Bell states and one n + 1-particle Greenberger–Horne–Zeilinger state with n agents, where the agent Bob, who is designated to recover the original m-qubit state, just keeps m particles and other agents (all controllers) n − 1 particles, that is, each controller only holds one particle in hand. Subsequently, Alice performs m Bell-basis measurements on her 2m particles and each controller only need take a single-particle measurement on his particle with the basis X. Finally, Bob can recover the original m-qubit state with the corresponding local unitary operations according to Alice and all controllers’ measurement results. Its intrinsic efficiency for qubits approaches 100%, and the total efficiency really approaches the maximal value, which is higher than those of the known symmetric schemes.     

Cyclic joint remote state preparation in noisy environment

We propose a scheme of cyclic joint remote state preparation for three sides, which takes advantage of three GHZ states to compose product state as quantum channel. Suppose there are six legitimate participants, says Alice, Bob, Charlie, David, Emma and Fred in the scheme. It can be shown that Alice and David can remotely prepare a single-qubit state on Bob’s side; meanwhile, Bob and Emma can remotely prepare a desired quantum state on Charlie’s side, and Charlie and Fred can also remotely prepare a single-qubit state on Alice’s side at the same time. Further, it can be achieved in the opposite direction of the cycle by changing the quantum channel. Based on it, we generalize this protocol to \(N (N\ge 3)\) sides utilizing three multi-qubit GHZ-type states as quantum channel. Therefore, the scheme can achieve cyclic joint remote state preparation, which remotely prepares N states in quantum network with N-party, simultaneously. In addition, we consider that the effect of amplitude-damping noise of the initial states is prepared in four different laboratory. Clearly, we use fidelity to describe how much information has been lost in the cyclic process. Our investigation about the effect of noise shows that the preparing of the initial state in different laboratories will affect the loss of information.     

Cluster态的量子签名方案

提出一种利用Cluster state纠缠态实现的量子签名方案。该方案中用Cluster态作为量子信道,每一组量子比特串分别分发给消息拥有和签名者Alice、公证人TA、验签名者Bob。加载消息的方法是Alice在TA规定量子比特串序列下,分别对拥有的量子比特对的第一个量子比特进行幺正变换操作而进行。对拥有的量子比特对进行的Bell测量结果是消息的签名。Bob对拥有的对应的两个量子比特对进行Bell测量来验证签名,但要得到公证人TA对其约束才能完成。Cluster state纠缠态在纠缠特性、局域操作保真性和安全性有较好的性能。     

Controlled teleportation

In this article, we review the recent development of controlled teleportation which can be used for sharing quantum information and has important applications in remote quantum computation. We introduce the principles of a couple of controlled teleportation schemes with maximally entangled quantum channels and those with pure entangled quantum channels (non-maximally entangled states). The schemes based on maximally entangled states have the advantage of having maximal efficiency although there are differences in their implementations in experiment. In the controlled teleportation schemes using non-maximally entangled states as the quantum channels, the receiver can reconstruct the originally unknown state by adding an auxiliary particle and performing a unitary evolution. No matter what the unknown state is (a single qubit state or an m-qudit state), the auxiliary particle required is only a two-level quantum system.     

Quantum state sharing against the controller’s cheating

Most existing QSTS schemes are equivalent to the controlled teleportation, in which a designated agent (i.e., the recoverer) can recover the teleported state with the help of the controllers. However, the controller may attempt to cheat the recoverer during the phase of recovering the secret state. How can we detect this cheating? In this paper, we considered the problem of detecting the controller’s cheating in Quantum State Sharing, and further proposed an effective Quantum State Sharing scheme against the controller’s cheating. We cleverly use Quantum Secret Sharing, Multiple Quantum States Sharing and decoy-particle techniques. In our scheme, via a previously shared entanglement state Alice can teleport multiple arbitrary multi-qubit states to Bob with the help of Charlie. Furthermore, by the classical information shared previously, Alice and Bob can check whether there is any cheating of Charlie. In addition, our scheme only needs to perform Bell-state and single-particle measurements, and to apply C-NOT gate and other single-particle unitary operations. With the present techniques, it is feasible to implement these necessary measurements and operations.