利用弱测量和量子测量翻转方法克服纠缠退相干  

Overcoming decoherence of entanglement by weak measurement and quantum measurement reversal method

作　　者：丁东[1] 王粲 余明星 DING Dong;WANG Can;YU Mingxing(North China Institute of Science and Technology,Yanjiao,065201,China)

机构地区：[1]华北科技学院,北京东燕郊065201

出　　处：《华北科技学院学报》2022年第2期114-119,共6页Journal of North China Institute of Science and Technology

基　　金：河北省高等学校科学技术研究重点项目(ZD2021407);河北省高等教育教学改革研究与实践项目(2021GJJG482);中央高校基本科研业务费专项基金项目(3142019020)。

摘　　要：纠缠态是量子信息处理中的一种重要的物理资源,量子态在传输过程中会与环境产生不可避免的退相干。本文我们通过弱测量和量子测量翻转方法,来保护纠缠态免受振幅阻尼退相干信道的影响。以三体Wigner的朋友实验中的三量子比特态作为研究对象,计算不同退相干强度以及弱测量强度下,弱测量和量子测量翻转前后量子系统纠缠态的纠缠度与保真度。结果表明,量子态的纠缠度和保真度随弱测量强度变化,弱测量强度越大,保真度与纠缠度越大,甚至当弱测量强度足够大时,纠缠度和保真度可恢复至原值。可知弱测量和量子测量翻转方法确实有助于减轻或避免振幅阻尼量子信道中的退相干。As an important physical resource,entangled states act as an essential component in quantum information processing.Quantum state will inevitably decoherence with the environment in the process of transmission.The protection of quantum entangled states from amplitude damped decoherence channel was studied by using weak measurement and quantum measurement reversal methods.Taking the three-qubit state used in the tripartite Wigner's friend experiment as example,the entanglement measure and fidelity of that state before and after the weak measurement and quantum measurement reversal under different decoherence intensity was calculated.The entanglement and fidelity of quantum states vary with the intensity of weak measurement.The stronger intensity of the weak measurement,the greater the fidelity and entanglement.Even when the intensity of weak measurement is large enough,the entanglement measure and fidelity can be restored to the original value.It can be seen that the weak measurement and quantum measurement reversal method is indeed helpful to reduce or avoid decoherence in amplitude damping quantum channels.

关 键 词：弱测量 退相干 量子纠缠 

分 类 号：O436[机械工程—光学工程]