Deterministic Joint Remote State Preparation Research Articles

Joint remote state preparation in multi-hop network under noisy environment

Joint remote state preparation is an important method to transmit quantum information with more senders and higher security. In this paper, we present a deterministic joint remote state preparation scheme in multi-hop network with two senders and N intermediate parties, using only projective measurements and recovery operations. We describe the scheme under the framework of density matrix to investigate the performance of the scheme in noisy environment. The relation of fidelity, noise rate and the number of intermediate nodes is given for three types of noise. It is revealed that the average fidelity attains its minimum when the noise rate is at the most uncertain point, decreases monotonically as the number of intermediate nodes increases. However, in some special cases, the average fidelity of the multi-hop scheme is greater than some existing one step joint remote state preparation scheme.

Deterministic joint remote state preparation via a non-maximally entangled channel

Ideal deterministic quantum communication tasks require maximally entangled channels. The reality is that the maximally entangled channel is inevitably degraded to a generally entangled one because of various decoherence mechanisms, seriously deteriorating the performance of quantum communication. In most cases, entanglement purification and distillation are utilized to improve the entanglement and to construct the maximally entangled channel. In this paper, we proposed an alternative scheme to realize deterministic joint remote state preparation using a non-maximally entangled channel. Instead of spending additional entanglement resources in advance for entanglement purification or distillation, only two non-entangled ancillaries are employed in this scheme. Whether the employed quantum channel is a maximally entangled channel or a generally entangled one, remote state preparation would never fail theoretically in this investigation. This protocol provides a feasible way for the construction of practical quantum networks.

Enhanced deterministic joint remote state preparation under Pauli channels with memory

Joint remote state preparation (JRSP for short) can reduce the risk brought by one dishonest sender in remote state preparation. Unlike previous protocols that focused on JRSP under memoryless noise channels, in this paper, we study the performance of a deterministic joint remote state preparation scheme under two successive uses of Pauli channels with memory. We give general formulas quantifying the fidelity under the correlated Pauli channels. Specifically, we find that the performance of the protocol is enhanced in the correlated Pauli channel with partial memory. It means that the memory in this kind of noise channels can improve the communication efficiency of JRSP definitely.

Deterministic joint remote state preparation of arbitrary two-qubit state through noisy cluster-GHZ channel

We have investigated the effect of different quantum noises on deterministic joint remote state preparation of arbitrary two-qubit systems, carried out through the collective action on a coupled cluster-GHZ state without introducing auxiliary qubit. The present scheme is deterministic, in comparison to the existing probabilistic schemes. The selection of measurement bases plays a crucial role in the success of our scheme. We have demonstrated the effect of six distinct noises on information loss, quantified through the fidelity measure. The loss of information is found to be minimum for amplitude damping channel and is maximum for the bit-flip channel.

Joint remote state preparation of mixed states

Joint remote state preparation (JRSP) has gained much attention since its first appearance. However, almost all the proposals have focused on the JRSP of pure states. In this paper, we present a scheme of JRSP for mixed states via the three-qubit GHZ state. The scheme is deterministic for real coefficient mixed states and probabilistic for complex ones. The corresponding quantum circuits are given for the deterministic JRSP schemes. The model of the deterministic JRSP scheme is introduced in the language of density operators. Furthermore, we investigate the efficiency of deterministic JRSP when some qubits in the protocol are subjected to a noisy environment. Four types of noise usually encountered in quantum communication are considered, i.e. the bit-flip, phase-flip (phase-damping), depolarizing and amplitude-damping noise. We find that the fidelity is affected by both coefficients of the target mixed state and noise parameter of the channel. Specifically, the fidelity decreases with the purity parameter in the presence of noise.

Deterministic joint remote state preparation of four-qubit cluster type with tripartite involvement

Cluster state is deemed to be a significant quantum resource, for it can encode much information; its remote preparation is significant to the quantum information processing. In the paper, a novel joint remote quantum state preparation protocol is proposed, in which three participants are included, and they are cooperatively involved for the protocol accomplishment within the configuration constructed by the four-qubit cluster type and EPR pairs. The cluster-type state is successful prepared via the appropriate unitary operations after the relevant participants perform the projection measurement. The presented protocol shows highly secure and could stand against the external eavesdropper.

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.

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.

Effect of noise on deterministic joint remote preparation of an arbitrary two-qubit state

Quantum communication has attracted much attention in recent years. Deterministic joint remote state preparation (DJRSP) is an important branch of quantum secure communication which could securely transmit a quantum state with 100% success probability. In this paper, we study DJRSP of an arbitrary two-qubit state in noisy environment. Taking a GHZ based DJRSP scheme of a two-qubit state as an example, we study how the scheme is influenced by all types of noise usually encountered in real-world implementations of quantum communication protocols, i.e., the bit-flip, phase-flip (phase-damping), depolarizing, and amplitude-damping noise. We demonstrate that there are four different output states in the amplitude-damping noise, while there is the same output state in each of the other three types of noise. The state-independent average fidelity is presented to measure the effect of noise, and it is shown that the depolarizing noise has the worst effect on the DJRSP scheme, while the amplitude-damping noise or the phase-flip has the slightest effect depending on the noise rate. Our results are also suitable for JRSP and RSP.

Effect of quantum noise on deterministic joint remote state preparation of a qubit state via a GHZ channel

Quantum secure communication brings a new direction for information security. As an important component of quantum secure communication, deterministic joint remote state preparation (DJRSP) could securely transmit a quantum state with 100\% success probability. In this paper, we study how the efficiency of DJRSP is affected when qubits involved in the protocol are subjected to noise or decoherence. Taking a GHZ based DJRSP scheme as an example, we study all types of noise usually encountered in real-world implementations of quantum communication protocols, i.e., the bit-flip, phase-flip (phase-damping), depolarizing, and amplitude-damping noise. Our study shows that the fidelity of the output state depends on the phase factor, the amplitude factor and the noise parameter in the bit-flip noise, while the fidelity only depends on the amplitude factor and the noise parameter in the other three types of noise. And the receiver will get different output states depending on the first preparer's measurement result in the amplitude-damping noise. Our results will be helpful for improving quantum secure communication in real implementation.

Deterministic joint remote preparation of an arbitrary six-qubit cluster-type state

In this paper, we propose a feasible scheme for deterministic joint remote state preparation (JRSP) of an arbitrary six-qubit cluster-type state with the assistance of several GHZ entangled states and a two-qubit unitary operation. Firstly, Alice performs a two-qubit projective measurement according to the amplitude coefficients of the target state, and then Bob1 and Bob2 carries out other two projective measurements based on its phase coefficients. Next, a target two-qubit state is prepared with suitable operation. Finally, based on the arbitrary two-qubit state, the target six-qubit cluster-type state can be prepared by introducing four auxiliary particles and making appropriate local unitary operations with success probability 1. Furthermore, it’s worth noting that our scheme is more security and feasible with the present technologies than most other previous schemes.

Deterministic joint remote state preparation via partially entangled quantum channel

In this paper, we propose a scheme for deterministic joint remote state preparation (JRSP). Two spatially separated senders intend to help a receiver remotely prepare an arbitrary single-qubit state. Four-particle partially entangled state is constructed to serve as the quantum channel. By determining right unitary operations for the senders and appropriate recovery operations for the receiver, the target state can be reestablished with unit success probability, irrespective of the channel parameter.

Deterministic joint remote state preparation of arbitrary single- and two-qubit states**Project supported by the National Natural Science Foundation of China (Grant Nos. 61372076 and 61301171), the 111 Project (Grant No. B08038), and the Fundamental Research Funds for the Central Universities, China (Grant No. K5051201021).

In this paper, two novel schemes for deterministic joint remote state preparation (JRSP) of arbitrary single- and two-qubit 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 joint remote preparation of an arbitrary two-qubit state in noisy environments

Using four Einstein---Podolsky---Rosen (EPR) states as the shared quantum channel, we investigate the deterministic joint remote preparation of an arbitrary two-qubit state in the presence of noisy environments through the analytical solution of the master equation in the Lindblad form. By means of unitary matrix decomposition method, quantum logic circuit for the deterministic joint remote state preparation (JRSP) protocol is first constructed. Then, we analytically derive the average fidelities of the deterministic JRSP process under the influence of Pauli noises, zero-temperature and high-temperature reservoirs acting on the four EPR pairs. It is found that the average fidelities under the action of different noises display different evolution behaviors. Moreover, for the specific noises examined in this paper, in the long-time limit, the dephasing noise and the zero-temperature environment have the relatively weak effect on their respective average fidelities, whereas the isotropic noise and the high-temperature environment have the relatively strong effect.

Improved Deterministic N-To-One Joint Remote Preparation of an Arbitrary Qubit via EPR Pairs

Recently, Bich et al. (Int. J. Theor. Phys. 51: 2272, 2012) proposed two deterministic joint remote state preparation (JRSP) protocols of an arbitrary single-qubit state: one is for two preparers to remotely prepare for a receiver by using two Einstein-Podolsky-Rosen (ERP) pairs; the other is its generalized form in the case of arbitrary N (N > 2) preparers via N ERP pairs. While examining these two protocols, we find that the success probability for the receiver achieving the desired state is not deterministic, i.e., \(P^{N>2}_{suc}<1\), for N > 2 preparers in the second protocol. Through constructing two sets of adaptive projective measurement bases for both the real space and the complex space, an improved deterministic N-to-one JRSP protocol for an arbitrary single-qubit state is presented. Analysis shows our protocol can truly achieve the unit success probability, i.e., \(P^{N\geq 2}_{suc}=1\). What is more, the receiver can be randomly assigned even after the distribution of the qubits of EPR pairs, so it is more flexible and applicable in the network situation.

Joint remote preparation of an arbitrary five-qubit Brown state via non-maximally entangled channels

We firstly present a novel scheme for deterministic joint remote state preparation of an arbitrary five-qubit Brown state using four Greenberg—Horme—Zeilinger (GHZ) entangled states as the quantum channel. The success probability of this scheme is up to 1, which is superior to the existing ones. Moreover, the scheme is extended to the generalized case where three-qubit and four-qubit non-maximally entangled states are taken as the quantum channel. We simultaneously employ two common methods to reconstruct the desired state. By comparing these two methods, we draw a conclusion that the first is superior to the second-optimal positive operator-valued measure only taking into account the number of auxiliary particles and the success probability.

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.

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.

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

We propose a novel deterministic protocol that two senders are capable of remotely preparing arbitrary two- and three-qubit states for a remote receiver using EPR pairs and GHZ state as the quantum channel. Compared with the existing deterministic protocols [An et al. 2011 Phys. Lett. A 375 3570 and Chen et al. 2012 J. Phys. A: Math. Theor. 45 055303], the quantum resources and classical information in our scheme are decreased, and the whole operation process is simplified.

Joint remote state preparation of arbitrary two-particle states via GHZ-type states

The protocols for joint remote preparation of an arbitrary two-particle pure state from a spatially separated multi-sender to one receiver are presented in this paper. We first consider the situation of two sender and demonstrate a flexible deterministic joint remote state preparation compared with previous probabilistic schemes. And then generalize the protocol to multi-sender and show that by only adding some classical communication the success probability of preparation can be increased to four times. Finally, using a proper positive operator-valued measure instead of usual projective measurement, we present a new scheme via two non-maximally entangled states. It is shown that our schemes are generalizations of the usual standard joint remote state preparation scheme and more suitable for real experiments with requirements of only Pauli operations.