基于自适应泡利测量的量子纯态层析方法  

Pure state tomography with adaptive Pauli measurements

作　　者：孟祥瑞 何明根[1,2] 苑震生 Xiangrui Meng;Minggen He;Zhensheng Yuan(Hefei National Research Center for Physical Sciences at the Microscale and School of Physics,University of Science and Technology of China,Hefei 230026,China;CAS Center for Excellence in Quantum Information and Quantum Physics,Hefei 230026,China)

机构地区：[1]合肥微尺度物质科学国家研究中心,中国科学技术大学物理学院,安徽合肥230026 [2]中国科学院量子信息与量子科技创新研究院,安徽合肥230026

出　　处：《中国科学技术大学学报》2022年第8期1-6,69,共7页JUSTC

基　　金：supported by the National Natural Science Foundation of China(12125409)。

摘　　要：量子态层析是对量子资源进行验证与充分利用的有力工具。然而,目前的纯态信息完备测量方案通常需要用到多比特量子门或者复杂的量子算法,它们在较大的量子系统中是难以实现的。本文提出了一种基于自适应泡利测量的N比特量子纯态层析方案。方案的第一步是在Z方向上对每个量子比特进行投影测量,以确定目标态各基矢分量的振幅。随后,根据Z方向的测量结果可以递归地推导出一组泡利测量基,以确定各基矢分量的相位。对于常见的量子态,如簇态和W态等,依此方法推导出的泡利测量基的数量在O(N)量级。最后,我们利用神经网络算法对一维链状纠缠态进行了重构,从而数值地验证了该方案的可行性。Quantum state tomography provides a key tool for validating and fully exploiting quantum resources. However,current protocols of pure-state informationally-complete(PS-IC) measurement settings generally involve various multiqubit gates or complex quantum algorithms, which are not practical for large systems. In this study, we present an adaptive approach to N-qubit pure-state tomography with Pauli measurements. First, projective measurements on each qubit in the Z-direction were implemented to determine the amplitude of each base of the target state. Then, a set of Pauli measurement settings was recursively deduced by the Z-measurement results, which can be used to determine the phase of each base. The number of required measurement settings is O(N)Finally, we numerically verified the feasibility of our strategy by reconstructing a 1-D chain state using a neural network algorithm.

关 键 词：量子信息 量子态层析 泡利测量 神经网络 

分 类 号：O431.2[机械工程—光学工程]