The aim of this work is to investigate bidirectional quantum teleportation (BQT) of information, where a Bell state is considered as the quantum channel of the teleportation process. We consider that the Bell state is distributed by a noisy amplitude damping channel. We analyze the behavior of quantum Fisher information(QFI), which provides a tool to quantify the efficiency of bidirectional teleportation. Our results show that by using the weak measurement technique it is possible to mitigate the effect of the noise and enhance the bidirectional teleportation of relevant parameters.
The aim of this work is to investigate bidirectional quantum teleportation (BQT) of information, where a Bell state is considered as the quantum channel of the teleportation process. We consider that the Bell state is distributed by a noisy amplitude damping channel. We analyze the behavior of quantum Fisher information(QFI), which provides a tool to quantify the efficiency of bidirectional teleportation. Our results show that by using the weak measurement technique it is possible to mitigate the effect of the noise and enhance the bidirectional teleportation of relevant parameters.
The purport of quantum teleportation is to completely transfer information from one party to another distant partner. However, from the perspective of parameter estimation, it is the information carried by a particular parameter, not the information of total quantum state that needs to be teleported. Due to the inevitable noise in environments, we propose two schemes to enhance quantum Fisher information (QFI) teleportation under amplitude damping noise with the technique of partial measurements. We find that post-partial measurement can greatly enhance the teleported QFI, while the combination of prior partial measurement and post-partial measurement reversal could completely eliminate the effect of decoherence. We show that, somewhat consequentially, enhancing QFI teleportation is more economic than that of improving fidelity teleportation. Our work extends the ability of partial measurements as a quantum technique to battle decoherence in quantum information processing.
The purpose of quantum teleportation is to achieve perfect transmission of quantum information from one site to another distant site. In the teleportation process, the quantum system is inevitably affected by its surrounding environment, causing the system to lose its coherence, which will result in distortion of the transmitted information. In recent years, weak measurement and measurement reversal have been proposed to suppress the decoherence of quantum entanglement and protect some quantum states. On the other hand, quantum Fisher information (QFI) is an important physical quantity in quantum metrology, which can give the optimal value estimating the accuracy of parameters. As is well known, QFI is highly susceptible to environmental noise and can lead its measurement accuracy to decrease. Therefore, it is of great importance to examine how to protect QFI from being influenced by the external circumstance during the teleportation procedure. In this paper, we study how to improve the QFI of teleporting a single-qubit state via a Greenberger-Horne-Zeilinger state in a finite temperature environment with the technique of weak measurement and weak measurement reversal. According to different qubit transmission cases of three quantum teleportation schemes, we consider their respective QFIs in detail. After constructing the quantum logic circuit of each teleportation scheme, we first analyze the variance trend of QFI against the generalized amplitude damping noise parameters. Then by introducing weak measurement and measurement reversal on each noise particle of the three schemes, we optimize the related partial measurement parameters and explore the corresponding improved QFI, namely, the difference between the QFI with optimal partial measurements and that without partial measurements. We find that optimizing partial measurements can efficiently enhance the QFI of the teleported state for the three kinds of teleportation schemes at finite temperature. Moreover, with the value of p fixed, the lower the environment temperature, the larger the value of the improved QFI is. Our results could be useful in further understanding the applications of weak measurement and measurement reversal to the quantum communication process and may shed light on estimating some relevant quantum parameters and implementing quantum information tasks.
Abstract In this paper, we have investigated the teleportation of quantum Fisher information (QFI) for a single qubit system using a class of X-states as resources influenced by decoherence channels with memory, including amplitude-damping, phase-damping and depolarizing channels. Using the QFI to quantify the quality of teleportation, we first derive the explicit analytical results of QFIs with respect to the weight parameter ( ) and phase parameter ( ) under these decoherence channels, and find that both and are strongly dependent on the initial state’s parameters c i , noisy channel parameters D and , as well as the teleported state’s parameters and . For comparison with the teleportation of the single qubit case, we have also addressed the teleportation of QFI for a two-qubit entanglement system. The results show that , for a single qubit state, is more robust against noisy channels than that for a two-qubit state. However, for a two-qubit state is more robust than that of a single qubit state against noisy channels.
Recently, bidirectional quantum teleportation has attracted a great deal of research attention. However, existing bidirectional teleportation schemes are normally discussed on the basis of perfect quantum environments. In this paper, we first put forward a bidirectional teleportation scheme to transport three-qubit Greenberger–Horne–Zeilinger (GHZ) states based on controled-not (CNOT) operation and single-qubit measurement. Then, we generalize it to the teleportation of multi-qubit GHZ states. Further, we discuss the influence of quantum noise on our scheme by the example of an amplitude damping channel, then we obtain the fidelity of the teleportation. Finally, we utilize the weak measurement and the corresponding reversing measurement to protect the quantum entanglement, which shows an effective enhancement of the teleportation fidelity.
From the perspective of quantum information transmission, one may be interested in the teleportation of quantum Fisher information (QFI) which provides the optimal precision of parameter estimation. In this paper, we investigate the teleportation of QFI under the correlated amplitude damping (CAD) decoherence. It is found that the correlated effects play a positive role in improving the teleported QFI, but the impact of decoherence is still serious. Therefore, we propose two schemes, which are based on weak measurement (WM) and environment-assisted measurement (EAM), to enhance the teleportation of QFI under the CAD decoherence. The results show that both schemes can significantly improve the teleported QFI with a certain success probability. The findings of our study suggest that the correlated effects can significantly increase the success probabilities of these two schemes. A detailed comparison confirms that the EAM scheme is more efficient than the WM scheme in improving the teleportation of QFI.
Abstract In this suggested version of the bidirectional teleportation protocol, it is assumed that the used quantum channel passes through an amplitude damping channel. Therefore, some of its quantum correlations (entanglement) are lost and, consequently, its efficiency to implement this protocol decreases. The weak and the reversal measurements are used to recover the losses of these correlations, where the negativity, as a measure of entanglement is improved. In this context, we discussed the effect of the noisy strength on the fidelities of the bidirectional teleported states between the users. It is shown that, by applying the weak and the reversal measurements (WRM) on the initial quantum channel between the users, the fidelities of the teleported states are improved. Moreover, we showed that, the upper bounds of the teleported states depend on the initial states of the triggers and the strengths of WRM. It is worth noting that the WRM improves the quantum correlations of the shared channel and, hence, the fidelity of the teleported state if the initial fidelity of the teleported state is larger than 0.5.