摘要
在量子通讯的实验中,由于外界环境的影响,我们很难得到最大的纠缠纯态。量子信道可能以混合纠缠态的形式出现。而固体材料中的热平衡态就是一种重要的混合纠缠态。本文利用了两个独立的外加不均匀磁场的一维海森堡链的热纠缠态作为量子信道,实现了两粒子纠缠态的远程传送,分析了外界温度和磁场对纠缠和传输保真度的影响。为了突出传输效果,我们对平均保真度做了研究,结果发现当温度很低,外加反方向的磁场B1和B2时,平均保真度大于经典通道的传输极限值2/3。
In the experiment of quantum to the effects of environment. Therefore, The thermal equilibrium state in solid communication, maximal entangled pure states are difficult to got due a quantum channel is always represented by a form of mixed states state materials is one essential mixed entangled state. In this dissertation, a two - particle entangled state can be teleported through the channel of thermal mixed states in two independent 1 D Heisenberg chains. We study the effects of the non - uniform external magnetic field B and temperature T on the entanglement and fidelity. In order to characterize the quality of the teleported state, we make a research of the average fidelity FA. And when B1 and B2 have different directions, the entanglement teleportation is better than the classical teleportation under low temperature. At that case the average fidelity is always larger than 2/3 which is the limited value of the classical teleportation.
出处
《量子光学学报》
CSCD
北大核心
2009年第3期226-230,共5页
Journal of Quantum Optics
基金
国家自然科学基金(10774108)
关键词
量子纠缠
隐形传送
海森堡链
quantum entanglement
teleportation
Heisenberg chain
