Asymmetry and decoherence of a quantum channel in the quantum communication system of continuous variables

Abstract

Influences of an asymmetric noisy quantum channel on continuous variable entanglement and quantum teleportation are investigated. It is shown that when the resource of entanglement is a two-mode squeezed-vacuum state, the amount of the shared entanglement and the performance of the quantum teleportation are greater (smaller) in the symmetric quantum channel than in the asymmetric one if , where and are the average photon numbers of the two-mode squeezed-vacuum state and the thermal noise. When the quantum teleportation is carried out in the asymmetric quantum channel, introducing an additional loss makes better the performance of the quantum teleportation under certain conditions. The introduction of an additional loss makes smaller not only the shared entanglement but also the degree of the channel asymmetry.