Quantum communication is one of the cutting‐edge research areas today, where the scheme of remote state preparation (RSP) has drawn significant attention of researchers. The authors propose here a hierarchical RSP protocol for sending a two‐qubit entangled state using a seven‐qubit highly entangled state derived from Brown et al . state. They have also studied here the effects of two well‐known noise models namely amplitude damping (AD) and phase damping (PD). An investigation on the variation of the fidelity of the state with respect to the noise operator and receiver is made. PD noise is found to affect the fidelity more than the AD noise. Furthermore, the higher power receiver obtains the state with higher fidelity than the lower power receiver under the effect of noise. To the best of their knowledge, they believe that they have achieved the highest fidelity for the higher power receiver, 0.89 in the presence of maximum AD noise and 0.72 in the presence of maximum PD noise, compared to all the previously proposed RSP protocols in noisy environments. The study of noise is described in a very pedagogical manner for a better understanding of the application of noise models to a communication protocol.
Quantum communication is one of the cutting‐edge research areas today, where the scheme of remote state preparation (RSP) has drawn significant attention of researchers. The authors propose here a hierarchical RSP protocol for sending a two‐qubit entangled state using a seven‐qubit highly entangled state derived from Brown et al . state. They have also studied here the effects of two well‐known noise models namely amplitude damping (AD) and phase damping (PD). An investigation on the variation of the fidelity of the state with respect to the noise operator and receiver is made. PD noise is found to affect the fidelity more than the AD noise. Furthermore, the higher power receiver obtains the state with higher fidelity than the lower power receiver under the effect of noise. To the best of their knowledge, they believe that they have achieved the highest fidelity for the higher power receiver, 0.89 in the presence of maximum AD noise and 0.72 in the presence of maximum PD noise, compared to all the previously proposed RSP protocols in noisy environments. The study of noise is described in a very pedagogical manner for a better understanding of the application of noise models to a communication protocol.
Quantum communication is one of the cutting-edge research areas today, where the scheme of Remote State Preparation (RSP) has caught significant attention of researchers. A number of different schemes of RSP have already been proposed so far. We propose here a hierarchical RSP protocol for sending a two-qubit entangled state using a seven-qubit highly entangled state derived from Brown et al. state. We have also studied here the effects of two well known noise models namely amplitude damping (AD) and phase damping (PD) that affect the quantum communication channel used for the protocol. An investigation on the variation of fidelity of the state with respect to the noise operator and the receiver is made. PD noise is found to affect the fidelity more than the AD noise and the higher power receiver, obtains the state with higher fidelity than the lower power receiver under the effect of noise. To the best of our knowledge, we believe that we have achieved the highest fidelity for the higher power receiver, 0.89 in the presence of maximum AD noise and 0.72 in the presence of maximum PD noise, compared to all the previously proposed RSP protocols in noisy environments. The study of noise is described in a very pedagogical manner for better understanding of the application of noise models to a communication protocol.
Wang et al. first studied hierarchical quantum information splitting of an arbitrary single-qubit state via the [Formula: see text] state as the entangled channel. There exists a hierarchy among the three receivers as far as the power to recover the teleported state is concerned. But the scheme is considered in ideal environment. In this paper, we reinvestigate the scheme in amplitude-damping and phase-damping noises. The fidelity and average fidelity are adopted to quantify the effect of noise. It is found that they are both dependent on the coefficients of the teleported state and the noise parameter. Moreover, we put forward a novel deterministic scheme to realize hierarchical controlled remote preparation of an arbitrary single-qubit state. Comparing with the previous scheme via the [Formula: see text] state, the sender does not need to perform information dividing due to the subtly constructed measurement basis. We also consider the proposed scheme under noisy environment.
Quantum secure communication provides a new way for protecting the security of information. As an important component of quantum secure communication, remote state preparation (RSP) can securely transmit a quantum state from a sender to a remote receiver. The existence of quantum noise severely affects the security and reliability of quantum communication system. In this paper, we study the method for improving the efficiency of joint RSP (JRSP) subjected to noise with the help of weak measurement and its reversal measurement. Taking a GHZ based deterministic JRSP as an example, we utilize the technique of weak measurement and its reversal to suppress the effect of the amplitude-damping noise firstly. Our study shows that the fidelity of the output state can be improved in the amplitude-damping noise. We also study the effect of weak measurement and its reversal in other three types of noise usually encountered in real-world, namely, the bit-flip, phase-flip (phase-damping) and depolarizing noise. Our results show that the weak measurement has no effect for suppressing the bit-flip and phase-flip (phase-damping) noise, while has slight effect for suppressing the depolarizing noise. Our study is suitable for JRSP and RSP, and will be helpful for improving the efficiency of multiparticle entanglement based quantum secure communication in real implementation.
We propose a scheme for deterministic remote preparation of an arbitrary two-qubit state via a relay node. Afterwards, we investigate how the scheme is influenced by the noise type, the initial state to be remotely prepared, and the decoherence rate. We find that the fidelity is symmetrical with the line (λb-f=λp-f=0.5) in bit-flip and phase-flip channels. In addition, the fidelity decreases with the increase of decoherence rate in the amplitude-damping and phase-damping channels. We also compare it with other RSP schemes. Since only Bell pairs work as the quantum channels, it makes our RSP scheme more available and feasible.
Considering the difference in the ability of agents to prepare target state and the highly entangled nature of the Brown state, we propose a hierarchical remote preparation scheme to prepare an arbitrary two-qubit state via Brown state. There are four agents who are classified into two grades with respect to their abilities of restoring the target state. The upper-grade agent can accomplish the task with the help of any two remaining agents. While the agent at the lower grade requires the cooperation of all the other agents. Compared with previous hierarchical remote preparation schemes for an arbitrary two-qubit state, our scheme offers enhanced security by necessitating the collaboration of at least two other agents for any single agent to prepare the target state. It is worth mentioning that the recovery operation of an agent, whether he is of upper or lower grade, can be derived from the general expression, which clearly reveals the relationship with the measurement results. Moreover, we extend the proposed scheme to the case of an arbitrary multi-qubit state, thereby enhancing the capacity for quantum information transfer. Additionally, we evaluated the impact of amplitude-damping noise and phase-damping noise on the proposed scheme.
We investigate the influence of a noisy environment on the remote preparation of the multi-qubit equatorial state, and specifically deduce the final states and fidelities of the remote preparation of the three-qubit and four-qubit equatorial states under diverse types of noisy environments, namely, amplitude damping, bit flip, phase damping, phase flip, bit-phase flip, depolarization, and non-Markov environments. The results show that when the decoherence factors of the front six noises are equal, the influence degrees of phase damped noise, bit flip noise, phase flip noise, and bit-phase flip noise are similar, while the information loss caused by the amplitude damped noise and depolarizing noise is less. In particular, the bit flip noise and depolarizing noise may have more complex effects on the remote state preparation (RSP) schemes depending on the phase information of the target states, even for the ideal cases where the fidelity values are always 1 for specific phase relations. In the non-Markov environment, owing to the back and forth of information between the environment and systems, fidelities exhibit oscillating behavior and the minimum value may stay greater than zero for a long evolutionary time. These results are expected to have potential applications for understanding and avoiding the influence of noise on remote quantum communication and quantum networks.