Joint Remote Preparation Research Articles

Mentor initialed multiparty hierarchical joint remote preparation of an arbitrary n-qudit state via generalized Bell states

We propose a protocol to Mentor initiated hierarchical joint remote prepare the arbitrary n-qudit state with generalized Bell states.The agents share generalized Bell states with the Mentor. The Mentor performs five-qudit projective measurements on his entangled particles to initiate the quantum channel shared by the agents. All the senders share the information of the prepared state and make quantum measurements on their particles based on the state to be prepared. The agent in the upper grade needs only the assistance of one of the agents in the lower grade to reconstruct the original state, while the agents in the lower grade need the assistance of all the other agents to recover the original state. It is more convenient in application than others since the agents in the protocol only requires two-particle entanglement for Mentor initiated hierarchical joint remote preparation of an arbitrary n-qudit state.

Scrutinizing joint remote state preparation under decoherence

This research examines the effect of an open system containing the squeezed generalized amplitude damping channel on the joint remote preparation quantum communication protocol using a maximally entangled two-qubit state. Our findings indicate that the fidelity of a quantum system in contact with a non-zero temperature thermal bath can be enhanced by varying the squeezing parameters. These parameters include the squeezing phase of the channel Phi and the amount of squeezing of the channel r.

Enhancing the fidelity of joint remote state preparation by weak measurement

In this paper, the technique of weak measurement is employed in order to enhance the fidelity of joint remote state preparation (JRSP) protocol under decoherence. We design a quantum circuit of joint remote preparation of a single-qubit state through a GHZ state. Then, we analytically derive the average fidelity of the JRSP protocol under four types of noise usually encountered in real-world implementations of quantum communication protocols, i.e. the phase-flip, depolarizing, amplitude-damping and bit-flip noise. Our study shows that the application of weak measurement and measurement reversal could enhance the average fidelity of the JRSP process under the influence of phase-flip, depolarizing, amplitude-damping noise for most values of the decoherence parameters. If the JRSP process suffers from the bit-flip noise, the weak measurement technique is not useful for increasing the average fidelity.

Joint remote preparation of a single-photon hyper-state with two pairs of hyper-Bell states

Hyper-entanglement is gaining more and more attentions thanks to its outstanding applications in processing quantum information. It is considered as a quantum resource in many important tasks. In this work, we deal with a tripartite task for three remote parties Alice, Bob and Charlie. Namely, Alice and Bob are two senders who independently share the full information of an arbitrary single-photon state which is encoded simultaneously in two different degrees of freedom, the spatial-mode degree of freedom and the polarization degree of freedom (hereafter called photon’s hyper-state). We show that Alice and Bob can jointly prepare for the receiver Charlie such a hyper-state of the photon when they share beforehand two pairs of hyper-Bell states.

Effective deterministic joint remote preparation of the Knill–Laflamme–Milburn state in collective noise environment

Effective deterministic joint remote preparation of the Knill–Laflamme–Milburn state in collective noise environment

Multiparty probabilistic controlled joint remote preparation of an arbitrary <italic>m</italic>-qudit equatorial state with a pure entangled quantum channel

<p indent="0mm">The quantum equatorial state, a special kind of quantum state, has attracted much attention because of its potential for applications in quantum information processing. The remote preparations of arbitrary two-qudit, three-qudit equatorial and <italic>m</italic>-qudit equatorial states have been studied via different entangle quantum channels. In this paper, we propose two protocols for the controlled joint remote preparation of an arbitrary <italic>m</italic>-qudit equatorial state with a pure entangled quantum channel. The first is for the controlled joint remote preparation of the <italic>m</italic>-qudit equatorial state by using <italic>m</italic> multiparticle GHZ-class states as the quantum channel, and the second is for the controlled joint remote preparation of the <italic>m</italic>-qudit equatorial state via a multiparticle entangled state. All senders share information about the prepared state and perform <italic>m</italic>-particle projective measurements on their entangled particles according to their information about the prepared state. All controllers perform generalized X-basis measurements on their entangled particles. If a receiver cooperates with all the senders and controllers, he can prepare the original state probabilistically by performing unitary operations on his entangled particles and an auxiliary qubit. This protocol is more convenient for applications because it only requires nonmaximal entanglement for the controlled joint remote preparation of an arbitrary <italic>m</italic>-qudit equatorial state.

Joint remote preparation of single-photon three-qubit state with hyperentangled state via linear-optical elements

Transmitting quantum states securely and efficiently is an important task in quantum communication. In this article, we investigate the protocols for joint remote preparation of arbitrary three-qubit states with three-photon hyperentangled states simultaneously entangled in three degrees of freedom. First, we propose a protocol for deterministic joint remote preparation of a three-qubit state via a hyperentangled state simultaneously entangled in three degrees of freedom based on quantum state initialization. Second, we present a scheme for recursive joint remote preparation of the state via partially hyperentangled state, resorting to linear-optical elements only. The protocol has the advantage of having high channel capacity for joint remote preparing an arbitrary three-qubit state via hyperentangled state. Moreover, it is more convenient in application since it only requires linear-optical elements for joint remote preparation of arbitrary three-qubit state.

Joint multi-party remote preparation of arbitrary qudit states via a &amp;lt;italic&amp;gt;d&amp;lt;/italic&amp;gt;-level six-qudit Cluster state

We propose two protocols for joint, multi-party remote preparation of qudit states by using a d -level six-qudit Cluster state as the quantum channel. The first protocol is used for the joint remote preparation of an arbitrary two-qudit state via the d -level six-qudit Cluster state. The second is used for bi-directional joint remote preparation of an arbitrary single-qudit state via a d -level six-qudit Cluster state. All senders share information about the prepared state. The first sender applies Positive Operator-Valued Measurement (POVM) on her entangled particles in accordance with her information about the prepared state, while the second sender performs projective measurements in accordance with the information about the prepared state and the first sender’s measurement results. The receiver can prepare the original state by performing a corresponding unitary operation according to the measurement results from all the senders. These two protocols have the advantage of being able to provide a high channel capacity by using a d -level Cluster state as the quantum channel.

Effect of noise on joint remote preparation of an arbitrary two-qubit state via a Brown state

We present a scheme to realize joint remote state preparation (JRSP) of an arbitrary two-qubit state via a seven-qubit Brown state which is subjected to the noisy environment. Two basic noise models, the amplitude-damping noise and the phase-damping noise, are considered. The noise only affects the transmitted qubits of the quantum channel in our protocol. We put forward the detailed processes of JRSP protocol with these two kinds of noise. It is found out that the fidelities for both kinds of noise depend on the decoherence noisy rate and the amplitude factor of the prepared state. Interesting, the effect of phase-damping noise is much stronger than that of the amplitude-damping noise. Our study will contribute to the research on the effect of quantum noise for JRSP.

Controlled Joint Remote Preparation of a Six-Qubit Cluster-Type State by Using GHZ States

A scheme for the controlled joint remote preparation of an arbitrary six-qubit cluster-type state by using only two sets of five-qubit GHZ states as quantum channel is proposed. In our scheme, Alice firstly performs two sets of two-qubit projective measurement according to the real coefficients and the complex coefficients of the desired six-qubit cluster-type state. Then, the controller Charlie must apply another two-qubit projective measurement according to the Alice’s measurement result. Finally, Bob can obtain the desired six-qubit cluster-type state according to an appropriate unitary operation. Our scheme can achieve unit success probability.

Controlled joint remote preparation of an arbitrary N-qubit state

In this paper, a novel scheme for controlled joint remote preparation of an arbitrary N-qubit state is proposed. In the scheme, Alice and David prepare an arbitrary N-qubit state on Bob’s side under the control of Charlie by using a 3N + 1-qubit entangled state as the quantum channel. First, the quantum channel is constructed through the Hadamard and controlled-NOT operations. Then, Alice, David, and Charlie each perform the quantum measurements on their own qubits. To ensure that the original state can be prepared determinately, two algorithms are proposed to construct the measurement bases for Alice and David. Finally, Bob reconstructs the original state with several appropriate unitary operations on his qubits according to the measurement results of Alice, David, and Charlie. To demonstrate the feasibility of the scheme, a remote preparation example of an arbitrary two-qubit state with the scheme is given. At the end of this paper, the efficiency analysis of the scheme and some conclusions is presented. In comparison with previous schemes, the scheme is superior in terms of the capability and efficiency of quantum communication.

Deterministic joint remote preparation of arbitrary multi-qubit states via three-qubit entangled states

We propose an efficient scheme for joint remote state preparation (JRSP) of arbitrary multi-qubit states from two senders to one receiver with the 100% successful probability. Quantum channel is composed of maximally three-qubit entangled states, and several special mutually orthogonal measurement basis are constructed without the introduction of auxiliary particles. We also calculate the total classical communication cost required in the JRSP processes. The concrete JRSP procedures for remotely preparing single-qubit and two-qubit states are illustrated to prove explicitly the feasibility of this JRSP protocol.

Deterministic Joint Remote State Preparation of an Arbitrary Equatorial Three-Qubit State

We propose a new scheme for joint remote preparation of an arbitrary equatorial three-qubit state by using three three-qubit GHZ states as the quantum channel. In our scheme, eight different projective measurement basis vectors are needed. It is shown that the successful probability of our scheme is 100% by performing the appropriate unitary operations.

A highly efficient scheme for joint remote preparation of multi-qubit W state with minimum quantum resource

We present a highly efficient scheme for perfect joint remote preparation of an arbitrary $$ 2^{n} $$ -qubit W state with minimum quantum resource. Both the senders Alice and Bob intend to jointly prepare one $$ 2^{n} $$ -qubit W state for the remote receiver Charlie. In the beginning, they help the remote receiver Charlie to construct one n-qubit intermediate state which is closely related to the target $$ 2^{n} $$ -qubit W state. Afterward, Charlie introduces auxiliary qubits and applies appropriate operations to obtain the target $$ 2^{n} $$ -qubit W state. Compared with previous schemes, our scheme requires minimum quantum resource and least amount of classical communication. Moreover, our scheme has a significant potential for being adapted to remote state preparation of other special states.

Nonstandard protocols for joint remote preparation of a general quantum state and hybrid entanglement of any dimension

Joint remote state preparation (JRSP) is a useful way to securely transfer quantum information encoded in quantum states between distant places without physically sending the states themselves. In this paper we study JRSP of the most general D-dimensional quantum state called quDit state, with arbitrary integer D. We first show that, by standard procedures, i.e., by exploiting projective measurements on the Hilbert space of the systems of concern, this task can be completed for the dimensions 2, 4, or 8 only. We then propose a nonstandard protocol by means of a positive operator-valued measurement (POVM), which we suitably design so that our protocol works deterministically for any dimension. We also propose a nonstandard protocol for deterministic JRSP of arbitrary hybrid quDit-quNit entanglement with another POVM. Moreover, we construct quantum circuits to realize the two POVMs in the two nonstandard JRSP protocols mentioned above. Our results may be of interest not only from a theoretical point of view but also from an experimental one.

Coping with noise in joint remote preparation of a general two-qubit state by using nonmaximally entangled quantum channel

Noise is unavoidable in practice and its presence makes quantum protocols imperfect. In this paper we consider a way to cope with typical types of noise in joint remote preparation of an arbitrary 2-qubit state. The idea is to use nonmaximally (in stead of maximally) entangled states as the initial quantum channel. Because noise changes the initial quantum channel we can beforehand tailor it to be nonmaximally entangled by introducing free parameters which, depending on given types of noise, can be controlled so that due to the affect of noise the initial quantum channel becomes closest to the maximally entangled one, thus optimizing the performance of the joint remote state preparation protocol. The dependence of the optimal averaged fidelities on the strength of various types of noise is represented by phase diagrams that clearly separate the quantum domain from the classical one.

Deterministic joint remote preparation of an equatorial hybrid state via high-dimensional Einstein–Podolsky–Rosen pairs: active versus passive receiver

Entanglement plays a vital and in many cases non-replaceable role in the quantum network communication. Here, we propose two new protocols to jointly and remotely prepare a special so-called bipartite equatorial state which is hybrid in the sense that it entangles two Hilbert spaces with arbitrary different dimensions D and N (i.e., a type of entanglement between a quDit and a quNit). The quantum channels required to do that are however not necessarily hybrid. In fact, we utilize four high-dimensional Einstein–Podolsky–Rosen pairs, two of which are quDit–quDit entanglements, while the other two are quNit–quNit ones. In the first protocol the receiver has to be involved actively in the process of remote state preparation, while in the second protocol the receiver is passive as he/she needs to participate only in the final step for reconstructing the target hybrid state. Each protocol meets a specific circumstance that may be encountered in practice and both can be performed with unit success probability. Moreover, the concerned equatorial hybrid entangled state can also be jointly prepared for two receivers at two separated locations by slightly modifying the initial particles’ distribution, thereby establishing between them an entangled channel ready for a later use.

Joint Remote State Preparation of a Single-Atom Qubit State via a GHZ Entangled State

We proposed a physical protocol for the joint remote preparation of a single-atom qubit state via a three-atom entangled GHZ-type state previously shared by the two senders and one receiver. Only rotation operations of single-atom, which can be achieved though the resonant interaction between the two-level atom and the classical field, are required in the scheme. It shows that the splitting way of the classical information of the secret qubit not only determines the success of reconstruction of the secret qubit, but also influences the operations of the senders.

Multiparty-controlled Joint Remote Preparation of an Arbitrary m-qudit State with d-dimensional Greenberger-Horne-Zeilinger States

We present a scheme for multiparty-controlled joint remote preparation of an arbitrary m-qudit state by using d-dimensional Greenberger-Horne-Zeilinger (GHZ) states as the quantum channel. An arbitrary m-qudit state can be transmitted from two senders to a remote receiver in a quantum communication network under the controller’s control. The senders perform m-qudit measurements according to their information of prepared state, the controllers only need perform single-particle projective measurements. The receiver can prepare the original state on his quantum system by performing corresponding unitary operation according the measurement results of the senders and controllers. It is shown that an arbitrary m-qudit state in general form can be controlled joint remote prepared if and only if the receiver cooperates with all the senders and controllers.

Efficient schemes for deterministic joint remote preparation of an arbitrary four-qubit W-type entangled state

We present three schemes for the joint remote state preparation (JRSP) of an arbitrary four-qubit W-type entangled state with complex coefficients via four and two three-qubit GHZ states as the quantum channel. In these schemes, two senders (or N senders) share the original state which they wish to help the receiver to remotely prepare. To complete the JRSP schemes, some novel sets of mutually orthogonal basis vectors are introduced. It is shown that, only if two senders (or N senders) collaborate with each other, and perform projective measurements under suitable measuring basis on their own qubits, the receiver can reconstruct the original state by means of some appropriate unitary operations. It is shown that, in all our schemes, the total success probability of the JRSP can reach 1. Specially, compared with the first scheme in our paper, the entanglement resource in the second scheme can be reduced. This means that the scheme is more efficient and economical.