外场驱动下腔QED中实现任意两原子态的隐形传送方案

提出了一种外场驱动下在腔QED中实现任意两原子态隐形传送的方案.在隐形传送的过程中.以两原子最大纠缠态作为量子通道,不用考虑腔场耗散和外界热场环境的影响.在传送过程中包含着对原子的Bell基测量,但不需要直接进行Bell基测量,而且最终能成功实现传送的几率为1.0.同时这种方案也可以用来传送未知的三原子GHZ态,传送的几率也为1.0.     

Controlled Phase Flip Gate and Its Application in Low-Q Cavities by Single-Photon Input-Output Process

By employing an auxiliary cavity, we investigate the possibility to implement the conditional phase flip (CPF) gate on two atoms confined in separate low-Q cavities by single-photon input-output process, based on the Faraday rotation. This indicates a universal quantum computing available with sophisticated cavity QED techniques. As examples, we carry out generation of cluster states of distant atomic qubits and accomplish a teleportation based on Bell-state measurement in low-Q cavities.     

Controlled Phase Flip Gate and Its Application in Low-Q Cavities by Single-Photon Input-Output Process

By employing an auxiliary cavity, we investigate the possibility to implement the conditional phase flip (CPF) gate on two atoms confined in separate low-Q cavities by single-photon input-output process, based on the Faraday rotation. This indicates a universal quantum computing available with sophisticated cavity QED techniques. As examples, we carry out generation of cluster states of distant atomic qubits and accomplish a teleportation based on Bell-state measurement in low-Q cavities.     

Teleportation of Atomic States in a Vacuum-Induced Environment

We present a scheme for teleporting atomic state through a dissipative quantum channel induced by spontaneous emission and investigate the destructive effect of the atomic decay on the success probability and the fidelity of teleportation associated to different channels. It is found that there exists an optimal channel to realize faithful teleportation.     

Probabilistic teleportation of an unknown N-atom state using a two-atom nonmaximally entangled state in cavity QED

We present a scheme for realizing probabilistic teleportation of an unknown N-atom state via cavity QED. This scheme requires only a nonmaximally entangled pair to be used as a quantum channel, so the requirement of entanglement is reduced. In addition, our scheme does not involve the Bell-state measurement and is insensitive to the cavity decay, which is important from the experimental point of view. If the quantum channel is a two-atom maximally entangled state, teleportation of an unknown N-atom state can be realized by a simpler scheme via cavity QED.     

Teleportation of an Unknown Atomic Entangled State Without Any Joint Bell-state Measurement via a Cluster State

An experimentally feasible scheme for teleportation of an unknown two-atom entangled state is proposed. Our scheme uses a duster state as the quantum channel, where we do not need any joint Bell-state measurement. Moreover the successful probability and fidelity of teleportation can both reach 1.0. The current scheme can be realized within the current experimental technology.     

Quantum Teleportation and Quantum Information Splitting by?Using?a?Genuinely?Entangled Six-Qubit State

A new application of the genuinely entangled six-qubit state introduced recently by Tapiador et al. (J. Phys. A 42:415301, 2009) is investigated for the quantum teleportation of an arbitrary three-qubit state and for quantum information splitting (QIS) of an arbitrary two-qubit state. For QIS, we have shown that it can be completed perfectly with two distinct measurement methods. In our scheme, the joint Bell-state measurement and the joint multi-qubit measurement are needed. This quantum teleportation and QIS schemes are deterministic.     

Teleportation for atomic entangled state by entanglement swapping with separate measurements in cavity QED

Experimentally feasible scheme for teleportation of atomic entangled state via entanglement swapping is proposed in cavity quantum electrodynamics without joint Bell-state measurement. In the teleportation processes the interaction between atoms and a single-mode nonresonant cavity with the assistance of a strong classical driving field substitute the joint measurements. The discussion of the scheme indicates that it can be realized by current technologies.     

Quantum teleportation across a biological membrane by means of correlated spin pair dynamics in photosynthetic reaction centers

In the process coined quantum teleportation the complete information contained in an input quantum stateΨ _i is teleported to a distant location at which the original quantum state is regenerated as teleported output stateΨ _i. This paper presents the proof-of-feasibility concept of a quantum teleportation experiment during which an arbitrary input quantum state is teleported across a biological membrane. As particular aspect it is emphasized that all essential subprocesses of the usual quantum teleportation scheme are suggested to be realized by free running reaction processes in a biological membrane-bound reaction center complex with only one significant adaptation required at the input side. The first process of generation of a spin-correlated (Einstein-Podolsky-Rosen) pair of particles (Bell-state source) is a naturally occurring process realized in photosynthetic reaction centers by the primary processes of light-induced charge separation across the membrane. The second process is the so-called Bell-state measurement, which is able to store the complete information of the input quantum state. It is suggested to be realized by a fast spin-dependent recombination between one pair partner spin and a properly engineered input spin. Under suitable recombination conditions the remaining second pair partner spin, situated at the receiver location on the other side of the membrane, is shown to end up in the quantum state identical to that of the initial input state due to the fixed spin correlation of the Bell-state source and the particular spin selectivity of the recombination process. Thus, the input (spin) quantum state is teleported from the spin near the (electron charge) donor side to the acceptor side of the membrane-bound photosynthetic reaction center complex. A comprehensive discussion is presented for this quantum teleportation concept using photosynthetic reaction centers as the quantum channel of communication. Standard electron paramagnetic resonance techniques can be used to set up the input state and read out or hand over the output state for subsequent quantum information processing.     

Bidirectional Controlled Quantum Teleportation of Three-Qubit State by a New Entangled Eleven-Qubit State

In this paper, an improved controlled bidirectional quantum teleportation protocol of the special three-qubit state is proposed. In a little bit more detail, under the control of the third supervisor Charlie, Alice wants to send one special three-qubit entangled state to Bob, and at the meantime, Bob also wants to transmit another special three-qubit entangled state to Alice. In other words, both Alice and Bob can be the sender and receiver simultaneously. To achieve this aim, a specific eleven-qubit entangled state is shared among Alice, Bob and Charlie in advance acting as the quantum channel. Then, Alice and Bob first implement the GHZ-state measurement and Bell-state measurement respectively, and following Charlie’s single-qubit measurement. Finally, upon the foregoing measurement results, Alice and Bob can respectively implement the specific unitary operators on their local particles to recover the initial state transmitted by the other.

     

量子隐形传态的类簇态信道方案(英文)

提出了利用一个四粒子类簇态来实现一个任意两粒子态的隐形传送方案.如果接受者能根据发送者提供的测量信息对量子态实施一个合适的幺正变换,那么隐形传送就能以一定的概率实现.由于该方案中充当量子信道的是部分纠缠态,因此该方案比以前基于最大纠缠态的方案更具有现实意义.同时研究导出一个重要的结论:可以从一个四粒子类簇态(部分纠缠态)中以一定的概率提取出一个四粒子簇态(最大纠缠态),这个概率等于成功隐形传态的概率.     

Quantum teleportation by entanglement swapping with trapped ions

An effective teleportation scheme for an unknown ionic internal state via trapped ions is proposed without joint Bell-state measurement (BSM). In the constructed quantum channel process, we make use of entanglement swapping to avoid decrease in entanglement during the distributing of particles. Thus our scheme provides new prospects for quantum teleportation in a longer distance. The distinct advantage of our scheme is insensitive to the heating of vibrational mode. Furthermore, our scheme has no any individual optical access, and the successful probability also can reach 1.     

量子隐形传态的类簇态信道方案

提出了利用一个四粒子类簇态来实现一个任意两粒子态的隐形传送方案.如果接受者能根据发送者提供的测量信息对量子态实施一个合适的幺正变换,那么隐形传送就能以一定的概率实现.由于该方案中充当量子信道的是部分纠缠态,因此该方案比以前基于最大纠缠态的方案更具有现实意义.同时研究导出一个重要的结论：可以从一个四粒子类簇态（部分纠缠态）中以一定的概率提取出一个四粒子簇态（最大纠缠态）,这个概率等于成功隐形传态的概率.     

The Teleportation of an Unknown Quantum State in Ion-Trap Systems

We propose a scheme for the teleportation of an arbitrary quantum state in trapped ions. In this scheme, two pairs of maximally two-qubit entangled state are required as the quantum channel. This scheme does not involve apparent Bell-state measurement and is insensitive to the heating of the vibrational mode. The probability of the success in our scheme can reach 1.0.     

Long-distance quantum teleportation assisted with free-space entanglement distribution

Faithful long-distance quantum teleportation necessitates prior entanglement distribution between two communicated locations. The particle carrying on the unknown quantum information is then combined with one particle of the entangled states for Bell-state measurements, which leads to a transfer of the original quantum information onto the other particle of the entangled states. However in most of the implemented teleportation experiments nowadays, the Bell-state measurements are performed even before successful distribution of entanglement. This leads to an instant collapse of the quantum state for the transmitted particle, which is actually a single-particle transmission thereafter. Thus the true distance for quantum teleportation is, in fact, only in a level of meters. In the present experiment we design a novel scheme which has overcome this limit by utilizing fiber as quantum memory. A complete quantum teleportation is achieved upon successful entanglement distribution over 967 meters in public free space. Active feed-forward control techniques are developed for real-time transfer of quantum information. The overall experimental fidelities for teleported states are better than 89.6%, which signify high-quality teleportation.     

Controlled three-party communication using GHZ-like state and imperfect Bell-state measurement

We present a controlled three-party communication protocol using Greenberger-Horne-Zeilinger (GHZ)-like state and imperfect Bell-state measurement. Using the idea of controlled quantum teleportation, it can realize the secret information transmission between the legitimate participants under the control of the controller. It needs no unitary operation to recover the original state for the receiver, and it saves half of communication cost publicized by the sender. The order rearrangement of particles and data block transmission ensure the security of communication. With imperfect Bell-state measurement, it is tolerant of some noise effects and is feasible by using the present optical technique.     

Teleporting an Unknown Two-qubit Entangled State via Ion-Trap Systems

We propose a scheme for teleportation of an unknown two-qubit entangled state via trapped ions. In this scheme, we use the GHZ state as a quantum channel and the success probability can reach 1. The distinct advantage of our scheme is insensitive to the heating of the vibrational mode. In addition, Bell-state measurement is not required.     

Entanglement concentration and teleportation of multipartite entangled states in an ion trap

We propose an effective scheme for the entanglement concentration of a four-particle state via entanglement swapping in an ion trap. Taking the maximally entangled state after concentration as a quantum channel, we can faithfully and determinatively teleport quantum entangled states from Alice to Bob without the joint Bell-state measurement. In the process of constructing the quantum channel, we adopt entanglement swapping to avoid the decrease of entanglement during the distribution of particles. Thus our scheme provides a new prospect for quantum teleportation over a longer distance. Furthermore, the success probability of our scheme is 1.0.     

N粒子量子纠缠态的隐形传送

该文提出了一个利用N对二粒子纠缠态作为量子通道实现N粒子纠缠态的隐形传送的方案.发送者对需传送的N粒子量子态与属于自己的纠缠对中的粒子分别进行N次Bell基测量,并将测量结果通过经典通道告诉接受者,接受者根据这些信息对自己拥有的N个粒子进行相应的联合幺正变换,可使这N个粒子处于待发送的原始量子态,从而实现概率为1的量子态的隐形传送.     

基于五粒子团簇态实现经济和简单的二粒子任意态的可控隐形传态(英文)

通过对五粒子团簇态新应用的研究,提出了一个经济和简单的二粒子任意态的可控隐形传态方案.在这个方案中,发送者(Alice)、控制者(Charlie)和接收者(Bob)共享一个五粒子团簇态,发送者只需要执行Bell基测量,而控制者也仅需要执行单粒子投影测量.接受者根据发送者和控制者的测量结果,对自己拥有的粒子做适当的幺正变换,就可以重建发送者的二粒子任意态.这个可控隐形传态方案是决定性的,成功的概率为100%.与使用相同的量子信道进行二粒子任意态的可控隐形传送方案相比,不需要执行多粒子的联合测量,从而使得这个方案更加简单.