Efficient polarization-entanglement purification based on parametric down-conversion sources with cross-Kerr nonlinearity
Efficient polarization-entanglement purification based on parametric down-conversion sources with cross-Kerr nonlinearity
复制标题
基于交叉克尔非线性参量下转换源的高效偏振纠缠纯化
DOI：
10.1103/physreva.77.042308
复制
发表时间：
2008-04
影响因子：
2.9
通讯作者：
Sheng, Yu-Bo
中科院分区：
文献类型：
--
作者：
Deng, Fu-Guo;Zhou, Hong-Yu;Sheng, Yu-Bo
提出了一种基于两个交叉克尔非线性参量下转换源的纠缠纯化方法。它由两个过程组成。第一个是一个初级纠缠纯化协议的PDC源与无损量子非破坏（QND）探测器通过转移光子对的空间纠缠到它们的偏振。此时，QND检测器充当受控非（CNOT）门的角色。同时，它们还可以区分出空间模的光子数，为下一步纯化纠缠态提供了一个很好的方法。在纠缠纯化的第二个过程中，新的QND探测器被设计成充当CNOT门的角色。该协议具有产率高的优点，不需要基于线性光学元件的CNOT门，也不需要复杂的单光子探测器，这使得它在实际应用中更加方便。
We present a way for entanglement purification based on two parametric down-conversion (PDC) sources with cross-Kerr nonlinearities. It is comprised of two processes. The first one is a primary entanglement purification protocol for PDC sources with nondestructive quantum nondemolition (QND) detectors by transferring the spatial entanglement of photon pairs to their polarization. In this time, the QND detectors act as the role of controlled-NOT (CNOT) gates. Also they can distinguish the photon number of the spatial modes, which provides a good way for the next process to purify the entanglement of the photon pairs kept more. In the second process for entanglement purification, new QND detectors are designed to act as the role of CNOT gates. This protocol has the advantage of high yield and it requires neither CNOT gates based on linear optical elements nor sophisticated single-photon detectors, which makes it more convenient in practical applications.