The dynamics of the maximum entangled coherent state traveling through an amplitude damping channel is investigated. For small values of the transmissivity rate, the traveling state is very fragile to this noise channel, which suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate. As the number of modes increases, the traveling state over this noise channel quickly loses its entanglement. The odd and even states vanish at the same value of field intensity.
The dynamics of the maximum entangled coherent state traveling through an amplitude damping channel is investigated. For small values of the transmissivity rate, the traveling state is very fragile to this noise channel, which suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate. As the number of modes increases, the traveling state over this noise channel quickly loses its entanglement. The odd and even states vanish at the same value of field intensity.
The dynamics of maximum entangled coherent state travels through an amplitude damping channel is investigated. For small values of the transmissivity rate the travelling state is very fragile to this noise channel, where it suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate. As the number of modes increases, the travelling state over this noise channel loses its entanglement hastily. The odd and even states vanish at the same value of the field intensity.
The entanglement behavior for different classes of two-qubit systems passing through a generalized amplitude damping channel is discussed. The phenomena of sudden single and double changes and the sudden death of entanglement are reported for identical and nonidentical noise. It is shown that, for less entangled states, these phenomena appear for small values of channel strength. The effect of the channel can be frozen for these classes as one increases the channel strength. Maximum entangled states are more fragile than partial entangled states, where the entanglement decays very fast. However, one cannot freeze the effect of the noise channel for systems initially prepared in maximum entangled states. The decay rate of entanglement for systems affected by nonidentical noise is much larger than that affected by identical noise.
Preserving entanglement during the teleportation of multipartite quantum states is a central challenge in continuous-variable quantum communication, particularly when experimentally feasible finite-dimensional entangled resources are employed. In this work, we investigate whether the entanglement of a two-mode continuous-variable state can be preserved when only one of its modes is teleported through a multimode interferometry-based protocol using a three-dimensional discrete entangled channel. Two representative entangled states, namely the two-mode squeezed vacuum and discrete-modulation states, are considered under both ideal conditions and four standard quantum noise channels: bit-flip, phase-flip, depolarizing, and amplitude-damping. The protocol is evaluated in terms of teleportation fidelity, success probability, logarithmic negativity, Wigner-function evolution, and state purity to provide a comprehensive assessment of both teleportation quality and entanglement preservation. The results show that, in the absence of noise, the protocol preserves most of the initial entanglement while maintaining high teleportation fidelity. Under noisy conditions, the residual entanglement remains remarkably robust against amplitude-damping and phase-flip noise, whereas bit-flip noise causes the most pronounced degradation. The phase-space structure and purity of the teleported states are likewise largely retained over a broad range of noise strengths. These findings demonstrate that multimode interferometry with finite-dimensional entangled channels provides an effective and noise-resilient approach for preserving continuous-variable entanglement during quantum teleportation, offering a practical route toward realistic quantum communication networks.
Preserving entanglement during the teleportation of multipartite quantum states is a central challenge in continuous-variable quantum communication, particularly when experimentally feasible finite-dimensional entangled resources are employed. In this work, we investigate whether the entanglement of a two-mode continuous-variable state can be preserved when only one of its modes is teleported through a multimode interferometry-based protocol using a three-dimensional discrete entangled channel. Two representative entangled states, namely the two-mode squeezed vacuum and discrete-modulation states, are considered under both ideal conditions and four standard quantum noise channels: bit-flip, phase-flip, depolarizing, and amplitude-damping. The protocol is evaluated in terms of teleportation fidelity, success probability, logarithmic negativity, Wigner-function evolution, and state purity to provide a comprehensive assessment of both teleportation quality and entanglement preservation. The results show that, in the absence of noise, the protocol preserves most of the initial entanglement while maintaining high teleportation fidelity. Under noisy conditions, the residual entanglement remains remarkably robust against amplitude-damping and phase-flip noise, whereas bit-flip noise causes the most pronounced degradation. The phase-space structure and purity of the teleported states are likewise largely retained over a broad range of noise strengths. These findings demonstrate that multimode interferometry with finite-dimensional entangled channels provides an effective and noise-resilient approach for preserving continuous-variable entanglement during quantum teleportation, offering a practical route toward realistic quantum communication networks.
Using the algebraic dynamical method, the entanglement dynamics of an atom-field bipartite system in a mixed state is investigated. The atomic center-of-mass motion and the field-mode structure are also included in this system. We find that the values of the detuning and the average photon number are larger, the amplitude of the entanglement is smaller, but its period does not increase accordingly. Moreover, with the increase of the field-mode structure parameter and the transition photon number, the amplitude of the entanglement varies slightly while the oscillation becomes more and more fast. Interestingly, a damping evolution of the entanglement appears when both the detuning and the atomic motion are considered simultaneously.
In this paper, we investigate the entanglement dynamics of a two-qubit entangled state coupled with its noisy environment, and plan to utilize weak measurement and quantum reversal measurement to study the entanglement dynamics under different decoherence channels in noninertial frames. Through the calculations and analyses, it is shown that the weak measurement can prevent entanglement from coupling to the amplitude damping channel, while the system is under the phase damping and flip channels. This protection protocol cannot prevent entanglement but will accelerate the death of entanglement. In addition, if the system is in the noninertial reference frame, then the effect of weak measurement will be weakened for the amplitude damping channel. Nevertheless, for other decoherence channels, the Unruh effect does not affect the quantum weak measurement, the only exception is that the maximum value of entanglement is reduced to √2/2 of the original value in the inertial frames.