无噪线性放大的连续变量量子隐形传态

Continuous variable quantum teleportation with noiseless linear amplifier

连续变量量子隐形传态在实际的量子通信中起着至关重要的作用.然而,实际环境的噪声与损耗会导致量子纠缠的退化,极大地影响系统的传输性能,尤其是降低系统的传输距离,阻碍其实际应用.本文提出了无噪线性放大的连续变量量子隐形传态方案,利用无噪线性放大器对退化的纠缠源进行放大,从而补偿光纤损耗信道对纠缠源的衰减影响,提升系统的性能.本文详细分析了不同损耗信道和纠缠源情况下,无噪线性放大器的增益系数选取范围以及不同增益对方案性能的影响.仿真结果表明,本文提出的方案相比于原方案,在保真度和传输距离方面都有较大的提升.该研究结果为长距离连续变量量子隐形传态的实际应用提供了一种切实有效的方法.

Continuous variable quantum teleportation(CVQT)plays an important role in practical quantum communication.However,the noise and loss in the actual environment will lead to the degradation of entanglement,which has an effect on the performance of the system in terms of the transmission distance and hence hinders its implementations.In this paper,we suggest an approach to improving the performance of the CVQT system with an embedded noiseless linear amplifier(NLA).By using the NLA,one can amplify the degenerated entangled source to compensate for the attenuation of the fiber.Then we consider the influences of the available gains of the NLA on the performance of the proposed scheme under different lossy channels and entangled sources.The simulation results show that the performance is improved in fidelity and transmission distance,which may provide a feasible and effective method of putting the long-distance CVQT into practical application.