This study focuses on the impact of amplitude-damping noise, which diminishes the fidelity of the teleported quantum state on an existing cyclic quantum teleportation scheme [V. Verma, D. Yadav and D. K. Mishra, Opt. Quantum Electron. 53 (2021) 1]. The CQT scheme involves three participants performing a cyclic teleportation along with a controller to supervise the protocol. We also propose weak measurement and reversal measurement operations as potential solutions to combat the noise-induced decoherence and improve the fidelity of the existing CQT scheme. The simulation results showcase the improvements achieved in the fidelity calculation when implementing the potential solutions. The findings hold immense potential for quantum information communications in practical situations.
This study focuses on the impact of amplitude-damping noise, which diminishes the fidelity of the teleported quantum state on an existing cyclic quantum teleportation scheme [V. Verma, D. Yadav and D. K. Mishra, Opt. Quantum Electron. 53 (2021) 1]. The CQT scheme involves three participants performing a cyclic teleportation along with a controller to supervise the protocol. We also propose weak measurement and reversal measurement operations as potential solutions to combat the noise-induced decoherence and improve the fidelity of the existing CQT scheme. The simulation results showcase the improvements achieved in the fidelity calculation when implementing the potential solutions. The findings hold immense potential for quantum information communications in practical situations.
Abstract Driven by the development of quantum communication networks toward multi-user and high-security scenarios, this paper investigates controlled cyclic teleportation (CCT) in high-dimensional systems with diverse control modes. Three peer-level control models and two hierarchical control models are investigated, each with three users and three controllers. The corresponding CCT protocols are designed by establishing suitable entangled channels from an initial nine-qudit state. Classical information encoding is skillfully employed to reduce the classical communication overhead. Under the authorization of the controllers, each sender can deterministically teleport an arbitrary single-qudit state to her adjacent receiver. The receivers’ recovery operations are given by general expressions that explicitly reveal the dependence on the measurement outcomes. In addition, we systematically analyze the influence of amplitude damping noise in the three-dimensional system and improve the fidelity using environment-assisted measurement (EAM). Given favorable environmental measurement outcomes and successful reversal operations, the EAM strategy can conditionally restore unit fidelity under the optimal reversal condition, with the corresponding success probability explicitly quantified. Compared with existing CCT protocols, the proposed protocols are applicable to arbitrary-dimensional quantum states, support richer control modes within a unified framework, and provide quantitatively characterized anti-noise performance.
This study presents an improved quantum teleportation protocol designed to enhance fidelity in noisy environments by combining weak measurements (WMs) with flip and reversal operations. In our scheme, Alice prepares a four-qubit entangled state and shares one of the entangled qubits with Bob, which serves as the quantum channel for teleporting an arbitrary single-qubit state. Since the communication channel is subject to noise, Alice performs a weak measurement on the shared qubit before transmission to reduce the impact of decoherence. Building upon existing WM-flipreversal frameworks, we propose a modified weak measurement and reversal (WMR) protocol tailored for different noises in a four-qubit entangled system. The approach applies WM and flip operations prior to transmission to enhance resilience against noise, followed by corresponding reversal operations after transmission to recover the original quantum state. We systematically compare the performance of our proposed WMR protocol with the previously proposed WM-flip-reversal method under three common noise models: amplitude damping channel (ADC), phase flip channel (PFC), and bit flip channel (BFC). Our analysis reveals that the modified WMR scheme achieves significantly higher teleportation fidelity and improved robustness, particularly in bit flip noise environments. These findings highlight the potential of optimized weak measurement strategies for developing more reliable and noise-tolerant quantum communication protocols
A protective scheme of quantum dense coding and quantum teleportation of the X-type initial state is proposed in amplitude damping noisy channel with memory using weak measurement and measurement reversal. Compared with the noisy channel without memory, the memory factor improves both the capacity of quantum dense coding and the fidelity of the quantum teleportation to a certain extent for the given damping coefficient. Although the memory factor can inhibit decoherence in some degree, it cannot eliminate it completely. In order to further overcome the influence of the damping coefficient, the weak measurement protective scheme is proposed, which found that the capacity and the fidelity can be efficiently improved by adjusting weak measurement parameter. Another practical conclusion is that, among the three initial states, the weak measurement protective scheme has the best protective effect on the Bell-state in terms of the capacity and the fidelity. For the channel with no memory and full memory, the channel capacity of quantum dense coding reaches two and the fidelity of quantum teleportation reaches one for the bit system; the Bell system can recover the initial state completely with a certain probability. It can be seen that the entanglement of the system can be well protected by the weak measurement scheme, which provides a good support for the realization of quantum communication.
A scheme is proposed for cyclic-controlled quantum operation teleportation (CCQOT) for three sides with EPR and cluster states. Under the control of David, Alice can implement an unknown single-qubit unitary operation on the remote Bob’s quantum system, while Bob can execute a single-qubit unitary operation on Charlie’s quantum system and Charlie can also perform an unknown single-qubit unitary operation on Alice’s quantum system. Our scheme can be generalized to [Formula: see text]) agents involved in the cycle to realize the transmission of single-qubit operations. Moreover, by replacing the quantum channels, we can change the cyclic direction of controlled qunatum operation teleportation (CQOT) from clockwise to counterclockwise. In addition, we discuss our scheme in four types of noisy environments (amplitude-damping, phase-damping, bit-flip and phase-flip noisy environment), and use fidelity to analyze the amount of information lost in the process of CCQOT due to noise. The results show that the fidelity is determined by decoherence rate and amplitude parameters of the final state.
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 Noiseless quantum channels are critical to share a pure maximally entangled state for performing an ideal teleportation protocol. However, in reality the shared entanglement severely degraded due to decoherence. In this paper, we propose a quantum teleportation channel protection scheme to enhance the teleportation fidelity in presence of decoherence. Before the entangled pair enters the decoherence channel, the weak measurement and flip operations are applied to transfer the qubit to a more robust state to the effects of the noise. After the decoherence channel the reversed flip operations and weak measurement reversal are applied to recover the initial state. We illustrate our protected teleportation scheme and compare it with a protocol based on weak measurement reversal. The numerical results show that the average teleportation fidelity of our proposed scheme can be significantly improved. Although the proposed entanglement protection scheme is probabilistic, after a successful entanglement transmission, we use the standard teleportation protocol which has probability one.