Preserving entanglement and the fidelity of three-qubit quantum states undergoing decoherence using weak measurement

作     者：廖湘萍 方卯发 方见树 朱钱泉 

作者机构：College of ScienceHunan University of Technology College of Physics and Information ScienceHunan Normal University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2014年第23卷第2期

页      面：80-86页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：Project supported by the National Natural Science Foundation of China (Grant No.11074072) the Natural Science Foundation of Hunan Province of China (Grant No.10JJ3088) the Major Program for the Research Foundation of the Education Bureau of Hunan Province of China (Grant No.10A026) the Program for the Research Foundation of the Education Bureau of Hunan Province of China (Grant No.10C0658) 

主　　题：entanglement protection quantum fidelity weak measurement 

摘      要：We demonstrate a method to preserve entanglement and improve fidelity of three-qubit quantum states undergoing amplitude-damping decoherence using weak measurement and quantum measurement reversal. It is shown that we are able to enhance entanglement to the greatest extent, and to circumvent entanglement sudden death by increasing the weak measurement strength both for the GHZ state and the W state. The weak measurement technique can also enhance the fidelity to the quantum region and even close to 1 for the whole range of the decoherence parameter in both of the two cases. In addition, the W state can maintain more fidelity than the GHZ state in the protection protocol. However, the GHZ state has a higher success probability than the W state.