利用广义Bell态信道联合远程制备一个任意三量子比特态

研究了一个联合远程制备任意三量子比特态的方案。该方案利用广义的Bell态作为量子信道,两个发送者分别选择合适的测量基进行测量,然后利用经典信道把测量结果传送出去,接收者根据测量结果对自己手中的粒子采取适当的幺正操作,然后引入辅助粒子并进行选择性测量,就能概率性的得到想要制备的量子态。研究结果表明:利用不同形式的广义Bell态信道成功实现联合远程制备一个任意三量子比特态的概率是一样的,当量子信道处于最大纠缠态时,可以得到最大的成功概率。     

Deterministic joint remote preparation of an arbitrary two-qubit state in the presence of noise

Using two tripartite Greenberger-Horne-Zeilinger （GHZ） states as the shared channels, we investigate the noise effects on the deterministic joint remote preparation of an arbitrary two-qubit state. By unitary matrix decomposition procedure, we first construct the quantum logic circuit of the deterministic joint remote state preparation protocol. Then, we analytically derive the fidelity and the average fidelity for the deterministic joint remote preparation of an arbitrary two- qubit state and of four types of special two-qubit states under the influence of the Pauli noises. It is found that the fidelity depends on the noise types, the qubit-environment coupling strength, and the state to be remotely prepared. Moreover, even if the two GHZ channels are subject to the same environmental noises, the average fidelities for remotely preparing different two-qubit states display different time evolution behaviors. The remote preparation of the identical two-qubit states also shows that the average fidelities affected by different noisy environments exhibit different evolution actions.     

Quantum multicast schemes of different quantum states via non-maximally entangled channels with multiparty involvement

Due to the unavoidable interaction between the quantum channel and its ambient environment, it is difficult to generate and maintain the maximally entanglement. Thus, the research on multiparty information transmission via non-maximally entangled channels is of academic value and general application. Here, we utilize the non-maximally entangled channels to implement two multiparty remote state preparation schemes for transmitting different quantum information from one sender to two receivers synchronously. The first scheme is adopted to transmit two different four-qubit cluster-type entangled states to two receivers with a certain probability. In order to improve success probabilities of such multicast remote state preparation using non-maximally entangled channels, we put forward the second scheme, which deals with the situation that is a synchronous transfer of an arbitrary single-qubit state and an arbitrary two-qubit state from one sender to two receivers. In particular, its success probability can reach 100% in principle, and independent of the entanglement degree of the shared non-maximally entangled channel. Notably, in the second scheme, the auxiliary particle is not required.     

High efficient scheme for remote state preparation with cavity QED

In this paper, a scheme is proposed for remote state preparation （RSP） with cavity quantum electrodynamics （QED）. In our scheme, two observers share two-atom nonmaximally entangled state as quantum channels and can realize remote preparation of state of an atom. We also propose a generalization for remote preparation of N-atom entangled state by （N＋1）-atom GHZ-like state （N ≥ 2）. By this scheme, one single-atom projective measurement is enough for the RSP of a qubit or N-atom entangled state, and the probability of success for RSP is unity. Furthermore, we have considered the case where observers use W-like state as quantum channels to realize RSP of a qubit. We compare our scheme with existing ones.     

Analysis of Control Power in Controlled Remote State Preparation Schemes

We quantify and analyze the controller’s power in controlled remote state preparation schemes. Our analysis provides a lower bound on the control power required for controlled remote preparation of arbitrary D-dimensional states. We evaluate several existing controlled remote state preparation protocols and show that some proposed non-maximally entangled channels are not suitable for perfect controlled remote preparation of arbitrary quantum states from the controller’s point of view. We find that for remotely preparing D-dimensional states, the entropy of each controller should be no less than log2D bits. Our new criteria are not only useful for evaluating controlled remote state preparation schemes but can also be used for other controlled quantum communication schemes.     

Joint remote state preparation of a W-type state via W-type states

An all W-type state task is put forward: joint remote state preparation of a W-type state via W-type states. We propose two probabilistic yet faithful schemes for the task. The first scheme uses two arbitrary W-type states as the shared quantum resource and the second scheme exploits three such states. We show that, while the first scheme requires some additional quantum resource and technical operations from the receiver, the second scheme allows any completely unequipped party to play the role of receiver. In both schemes the classical communication cost is one bit per preparer.     

Probabilistic Remote Preparation of a Three-Particle Entangled State via Two Different Non-maximally Entangled Channels

We present two schemes for preparing remotely a three-particle entangled state by two different quantum channels. In the first scheme, two partial three-particle entangled states are used as the quantum channels, while in the second scheme, three two-particle non-maximally entangled states are employed as the quantum channels. It is shown that the remote state preparation can be successfully realized with certain probability, for both two schemes, if a sender performs some projective measurements and a receiver adopts some appropriate unitary transformations. It is shown also that the successful probabilities of these two schemes are different.     

Probabilistic Remote Preparation of a Three-Particle Entangled State via Two Different Non-maximally Entangled Channels

We present two schemes for preparing remotely a three-particle entangled state by two different quantum channels. In the first scheme, two partial three-particle entangled states are used as the quantum channels, while in the second scheme, three two-particle non-maximally entangled states are employed as the quantum channels. It is shown that the remote state preparation can be successfully realized with certain probability, for both two schemes, if a sender performs some projective measurements and a receiver adopts some appropriate unitary transformations. It is shown also that the successful probabilities of these two schemes are different.     

Scheme for Asymmetric and Deterministic Controlled Bidirectional Joint Remote State Preparation

The scheme for asymmetric and deterministic controlled bidirectional joint remote state preparation by using one ten-qubit entangled state as the quantum channel is proposed. In this scheme, Alice and David want to remotely prepare an arbitrary single-qubit state at Bob's site, at the same time, Bob and Eve wish to help Alice remotely prepare an arbitrary two-qubit entangled state. Alice and Bob can simultaneously prepare the desired states with the cooperation of David and Eve under the control of Charlie.     

利用纠缠交换在理想和非理想条件下的远程态制备(英文)

提出了利用纠缠交换技术实现一个纠缠态的远程制备.考虑在量子信道没有遭受噪声影响的条件下,利用一对两粒子纠缠态作为量子信道去实现远程态制备.此外我们考察了噪声存在时的远程态的制备,研究显示不同类型的量子噪声对远程态制备过程的保真度的影响不同.对一个确定量子态,我们考察了消相干效应对其远程制备的影响.     

Deterministic Joint Remote Preparation of an Arbitrary Two-Qubit State Using the Cluster State

Recently, deterministic joint remote state preparation (JRSP) schemes have been proposed to achieve 100% success probability. In this paper, we propose a new version of deterministic JRSP scheme of an arbitrary two-qubit state by using the six-qubit cluster state as shared quantum resource. Compared with previous schemes, our scheme has high efficiency since less quantum resource is required, some additional unitary operations and measurements are unnecessary. We point out that the existing two types of deterministic JRSP schemes based on GHZ states and EPR pairs are equivalent.     

Remote Operation on Quantum State Among Multiparty

In this paper, a scheme is proposed for performing remote operation on quantum state among multiparty. We use three-particle GHZ state as quantum channels to prepare a state operator, which describes quantum correlation between states and operations. Based on the special characteristic of the state operator, observers can perform unitary operation on a system that is away from observers. Our studies show this process is deterministic. We further consider remote operation among N spatially distributed observers, and the results show the successful realization of remote operation needs collective participation of N parties, that is, there exists strong correlation among multiparty. In addition, we investigate the case in which observers share a three-particle W state as quantum channels to perform remote operation and studies find this process is probabilistic.     

Remote Preparation of an Entangled State in Nonideal Conditions

In this paper, the theoretical investigation of remote preparation of an entangled state is studied in nonideal conditions. Our studies include two parts. In the first part, we consider the remote state preparation (RSP) of an entangled state through two equally noisy quantum channel states, namely, a mixture of Bell states. Studies show there is a particular mixed-state channel for which all pure entangled states remain entangled after this inexact RSP. In the second part, we suppose that noises which quantum channels suffer from can be expressed as the Lindblad operators.The master equation of the system can be expressed in the Lindblad form. Through solving the master equation, we calculate the fidelity as a function of decoherence rates and parameters of the state to be prepared. For a given entangled state, we investigate the influenceof different types of noises on the fidelity.     

Remote Preparation of an Entangled State in Nonideal Conditions

In this paper, the theoretical investigation of remote preparation of an entangledstate is studied in nonideal conditions. Our studies include two parts. In the first part, we consider the remote state preparation （RSP） of an entangled state through two equally noisy quantum channel states, namely, a mixture of Bell states. Studies show there is a particular mixed-state channel for which all pure entangled states remain entangled after this inexact RSP. In the second part, we suppose that noises which quantum channels suffer from can be expressed as the Lindblad operators. The master equation of the system can be expressed in the Lindblad form. Through solving the master equation, we calculate the fidelity as a function of decoherence rates and parameters of the state to be prepared. For a given entangled state, we investigate the influence of different types of noises on the fidelity.     

Efficient Joint Remote Preparation of an Arbitrary m-qudit State with Partially Entangled States

We present an efficient scheme for multiparty joint remote preparation of an arbitrary m-qudit state by using partially entangled states as the quantum channel. One of the senders first performs a collective unitary transformation on his entangled particles and the auxiliary qubit, and then he performs a Z-basis measurement on the auxiliary qubit for transforming the partially entangled quantum channel into the two types of multi-particle entangled states. In the first case, the quantum channel shared by all the senders and the receiver is the target channel. In the second case, the quantum channel transforms into another partially entangled state which is the resource for the quantum channel transformation in the next round. Compared with other protocols, our scheme has advantage of having high success probability for joint remote preparation of an arbitrary m-qudit state via partially entangled states.     

Two Schemes for Probabilistic Remote Preparation of a Four-Particle Entangled Cluster-Type State

Using partial entangled states as the quantum channel, two schemes for probabilistic remote preparation of the four-particle cluster-type state with real and complex coefficients are presented. In the first scheme, the sender and the receiver share two partial Bell states and one partial three-qubit GHZ stats as the quantum channel, and the sender can help a remote receiver to prepare a four-particle entangled cluster-type state by using three-qubit projective measurements with certain probability. In the second scheme, the quantum channel is composed of two partial three-qubit GHZ states, the remote state preparation （RSP） can be successfully realized via the positive operator valued measure （POVM）, and the two-particle projective measurements are also needed in this process. The total success probability and classical communication cost are calculated.     

A generalized tripartite scheme for splitting an arbitrary 2-qubit state with three 2-qubit partially entangled states and the Kraus measurement

We put forward a generalized tripartite scheme for splitting an arbitrary 2-qubit pure state with three 2-qubit non-maximally en-tangled states as quantum channels.The scheme for the first time incorporates the Kraus measurement into quantum information splitting scheme.In contrast to the similar scheme using the same quantum channels and the ancilla-entangled measurement,our scheme is superior in terms of operation and complexity,success probability,resource consumption and effciency.     

Efficient scheme for remote preparation of arbitrary n-qubit equatorial states

Recently,a scheme for deterministic remote preparation of arbitrary multi-qubit equatorial states was proposed by Wei et al.[Quantum Inf.Process.1770(2018)].It is worth mentioning that the construction of mutual orthogonal measurement basis plays a key role in quantum remote state preparation.In this paper,a simple and feasible remote preparation of arbitrary n-qubit equatorial states scheme is proposed.In our scheme,the success probability will reach unit.Moreover,there are no coefficient constraint and auxiliary qubits in this scheme.It means that the success probabilities are independent of the coefficients of the entangled channel.The advantage of our scheme is that the mutual orthogonal measurement basis is devised.To accomplish the quantum remote state preparation(RSP)schemes,some new sets of mutually orthogonal measurement basis are introduced.     

Deterministic joint remote state preparation of arbitrary single- and two-qubit states

In this paper, two novel schemes for deterministic joint remote state preparation(JRSP) of arbitrary single- and twoqubit states are proposed. A set of ingenious four-particle partially entangled states are constructed to serve as the quantum channels. In our schemes, two senders and one receiver are involved. Participants collaborate with each other and perform projective measurements on their own particles under an elaborate measurement basis. Based on their measurement results,the receiver can reestablish the target state by means of appropriate local unitary operations deterministically. Unit success probability can be achieved independent of the channel's entanglement degree.     

Deterministic Controlled Remote State Preparation of Real-Parameter Multi-Qubit States via Maximal Slice States

By exploiting three-qubit entangled states and appropriate measurement basis, we propose efficient protocols for deterministic controlled remote state preparation of arbitrary real-parameter multi-qubit states, in which the maximal slice states are used as quantum channel. The successful probability of our schemes can reach up to 100% by using multi-qubit mutually orthogonal measurement basis without the introduction of auxiliary particles. Based on the implementation schemes for preparing arbitrary two- and three-qubit states with real parameters, we have derived the controlled remote state preparation protocols for arbitrary real-parameter multi-qubit states.