Effects of Markovian and Non-Markovian Environments on Quantum Teleportation

Liang-Ming He ； Nong Wang

《Chinese Journal of Physics》 預刊文章 Pp. 63-74

https://doi.org/10.6122/CJP.20150107

並列摘要

We investigate the fidelity and the linear entropy of teleportation using a shared two qubit initially maximally entangled state as a quantum channel, in which one qubit interacts with a two-state system named as the probe particle in a reservoir by dispersive atom-field coupling. Without the coupling of the probe particle with the reservoir, the quantum channel state is a pure state but not an initially maximally entangled state under the influence of the probe particle, and thus Bob obtains a pure state with an average fidelity fluctuating between 2/3 and 1 with time t. In the cases of the probe particle coupling with the reservoir the Markovian and non-Markovian dynamics of such a quantum channel are discussed in detail to show the influence of the reservoir on teleportation. The quantum channel state is a mixed state, but its entanglement does not die under the influence of the reservoir. It is found that, for a given teleported state, the fidelity and the linear entropy both evolve asymptotically to their fixed values, respectively, which are relative to the decay rate γ (Markovian) or to the pseudomode decay rateΓ (non-Markovian). Furthermore, when time t≫γ^(-1) and t≫Γ^(-1), the average fidelity increases with the augments of γ andΓ, while it decreases with the aggrandizement of the dispersive interaction strength κ.