In this paper, an optimal asymmetric controlled teleportation protocol is proposed, where a three-dimensional (3D) GHZ entangled state is utilized to teleport an arbitrary unknown two-dimensional (2D) qubit and the correlation between the two entangled qutrits caused by their continuous transmission through a noisy channel is considered. We design a high-dimensional feed-forward control operator and use weak measurement reversal instead of the unitary operations in standard teleportation to mitigate the reduction in fidelity caused by noise. We further derive the average fidelity and overall success probability of the proposed teleportation protocol, and simulate its performance under correlated amplitude damping (CAD) and amplitude damping (AD) noise channels. The simulation results show that our protocol significantly improves the average fidelity under CAD noise. In particular, under AD noise, the average fidelity remains constant at 1. Moreover, we derive the optimal overall success probability without compromising fidelity. To verify the superiority of the feed-forward control method, we also calculate and analyze the performance of an asymmetric controlled teleportation protocol using only environment-assisted measurement (EAM), and compare it with the performance of our protocol through simulation. The results demonstrate that our protocol outperforms the protocol using only EAM methods in both CAD and AD noise.
In this paper, an optimal asymmetric controlled teleportation protocol is proposed, where a three-dimensional (3D) GHZ entangled state is utilized to teleport an arbitrary unknown two-dimensional (2D) qubit and the correlation between the two entangled qutrits caused by their continuous transmission through a noisy channel is considered. We design a high-dimensional feed-forward control operator and use weak measurement reversal instead of the unitary operations in standard teleportation to mitigate the reduction in fidelity caused by noise. We further derive the average fidelity and overall success probability of the proposed teleportation protocol, and simulate its performance under correlated amplitude damping (CAD) and amplitude damping (AD) noise channels. The simulation results show that our protocol significantly improves the average fidelity under CAD noise. In particular, under AD noise, the average fidelity remains constant at 1. Moreover, we derive the optimal overall success probability without compromising fidelity. To verify the superiority of the feed-forward control method, we also calculate and analyze the performance of an asymmetric controlled teleportation protocol using only environment-assisted measurement (EAM), and compare it with the performance of our protocol through simulation. The results demonstrate that our protocol outperforms the protocol using only EAM methods in both CAD and AD noise.
This paper presents a tripartite quantum teleportation protocol that incorporates feed-forward control and environment-assisted measurement, aiming to suppress the influence of arbitrary noise with at least one reversible Kraus operator. In this protocol, the feed-forward control is first utilized before the decoherence channel, such that the entangled qubit is transferred to the target state, which is more robust against noise. Next, the measurement is performed on the noise environment coupled with the entangled qubit during the decoherence channel. Finally, the reversed feed-forward control and the redesigned weak measurement reversal operator are applied after the decoherence channel. This protocol can be applied to the case where both amplitude damping and phase damping noise coexist. Based on this protocol, the analytical expressions for performance metrics including the average fidelity and the success probability are further derived. Even for the heavy damping cases, the final average teleportation fidelity can reach 1, which is independent of the magnitude of decoherence and the entanglement parameters. Furthermore, we optimize the success probability without compromising fidelity, and derive the average fidelity expression of the standard tripartite teleportation protocol through the phase damping noise channel. The effectiveness of our protocol is verified by numerical simulations.
A perfect teleportation protocol requires pure maximally shared entangled states. While in reality the shared entanglement is drastically degraded due to the inevitable interaction with the noisy environment. Here, we propose a teleportation protocol to teleport an unknown qubit through amplitude damping channels with a fidelity up to one with a single copy of the entangled state. Our proposed teleportation protocol, while illustrated using the Bell and W entangled states as examples, can be utilized with any type of entangled states. In our protocol, we utilize environment-assisted measurement (EAM) during the entanglement distribution, and further modify the original teleportation protocol to apply weak measurement in the last step of teleportation. We find a balance between teleportation fidelity and success probability by varying the strength of the weak measurement. Furthermore, we investigate the protection of third-party assisted teleportation protocols, where all the qubits of the entangled state pass through the amplitude damping channel. In particular, for the third-party assisted teleportation with the W state, the decoherence of the shared entanglement can be totally suppressed by using EAM, hence no weak measurement is required to achieve an average teleportation fidelity of unity. The numerical simulation results reveal that our proposed teleportation protocol outperforms both the weak measurement based probabilistic teleportation protocol and the original teleportation protocols without protection.
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.
Abstract The purpose of this paper is to further investigate the correlated and memory effects in 3D-Pauli-like noisy channels for controlled teleportation of an arbitrary unknown single-qutrit state. We first construct a three-qutrit maximally entangled state in a three-dimensional (3D) Hilbert space and subsequently propose a 3D controlled quantum teleportation (CQT) scheme for an arbitrary unknown single-qutrit state using the constructed three-qutrit maximally entangled state as the quantum channel. In this ideal case, through a few simple 3D unitary operations, the two communicating parties can perfectly accomplish the teleportation task under the supervision of the controller. Subsequently, we examine the performance of this CQT scheme under two successive uses of a 3D-Pauli-like noisy channel with memory, where the noise errors are categorized into four types: trit-flip, t-phase-flip, trit-phase-flip, and t-depolarizing. For each noise type, an analytical expression of the average fidelity is derived as a function of both the noise and memory parameters. Specifically, we find that, regardless of the noise strength, memory enhances the average fidelity for trit-flip and t-depolarizing noises, whereas for t-phase-flip and trit-phase-flip noises, memory reduces the average fidelity once the noise intensity exceeds a certain threshold. This indicates that in the first two noisy channels, memory can improve the communication efficiency of CQT, while in the latter two, excessive noise causes memory to diminish the teleportation performance.
The quantum teleportation is an emerging communication technology based on the principles of quantum mechanics. It utilizes the properties of quantum entanglement and quantum superposition to achieve secure transmission of information. Most of the current quantum teleportation protocols are analyzed under ideal environment, and merely realized the transmission of either single or two particle unknown quantum states between two participants. In this paper, by using eleven entangled quantum states as a quantum channel, we propose a cyclic and asymmetric novel protocol for four participants. The communication task is achieved by employing GHZ state measurement (GHZ), single-qubit measurement (SM), and unitary operations (UO) as the foundation of this protocol. Analysis demonstrates that the success probability of the proposed protocol can reach 100%. Furthermore, considering that in actual production environments, it is difficult to avoid the occurrence of noise in quantum channels, this paper also analyzes the changes in fidelity in two types of noisy scenarios: bit-flip noise, phase-flip noise. Showing that communication quality only depends on the amplitude parameters of the initial state and decoherence rate. Finally, we give a comparison with previous similar schemes in terms of achieved method and intrinsic efficiency, which illustrates the superiority of our protocol.
Most existing quantum teleportation schemes do not consider the memory effect of noise, which is becoming increasingly serious in practical quantum communication. In this paper, we propose two quantum teleportation protocols for noisy memory channels: one based on pre-flipping (PF) and another incorporating pre-flipping with environment-assisted measurement (PF-EAM). In the PF protocol, a pre-flipping operation is applied to the entangled qubits before entanglement distribution to enhance robustness against noise. A recovery operator is then used to reverse the pre-flipping operation. In the PF-EAM protocol, environment-assisted measurement (EAM) is added to the entanglement distribution process, further improving teleportation fidelity. Since the pre-flipping operator in the two protocols is a fixed unitary operator, our protocols exclude additional parameters, which is unlike weak measurement (WM) schemes that rely on adjustable measurement strength. We derive the analytical expressions for the average fidelity and the success probability of our teleportation protocols. The results show that the pre-flipping operator in the PF protocol effectively enhances the average fidelity of quantum teleportation in a deterministic manner, while the fidelity of PF-EAM remains at constant 1, unaffected by the noise intensity in the channel. In addition, our PF-EAM achieves a higher success probability while maintaining the fidelity of 1 with respect to the existing unprotected teleportation protocol, protocol based on weak measurement and measurement reversal (WM-MR), and protocol based on quantum feed-forward control and environment-assisted measurement (QFFC-EAM) framework.