Direct Strong Measurement of a High-Dimensional Quantum State  

作　　者：Chen-Rui Zhang Meng-Jun Hu Guo-Yong Xiang Yong-Sheng Zhang Chuan-Feng Li and Guang-Can Guo 张宸睿;胡孟军;项国勇;张永生;李传锋;郭光灿(CAS Key Laboratory of Quantum Information,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]CAS Key Laboratory of Quantum Information,University of Science and Technology of China,Hefei 230026,China [2]CAS Center For Excellence in Quantum Information and Quantum Physics,Hefei 230026,China

出　　处：《Chinese Physics Letters》2020年第8期7-11,共5页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(Grant Nos.11574291,11774334,11774335,11674306 and 61590932);the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB01030200);the National Key Research and Development Program of China(Grant Nos.2016YFA0301300,2016YFA0301700 and 2017YFA0304100);the Key Research Program of Frontier Science,CAS(Grant No.QYZDY-SSW-SLH003);Anhui Initiative in Quantum Information Technologies.

摘　　要：It is of great importance to determine an unknown quantum state for fundamental studies of quantum mechanics,yet it is still difficult to characterize systems of large dimensions in practice.Although the scan-free direct measurement approach based on a weak measurement scheme was proposed to measure a high-dimensional photonic state,how weak the interaction should be to give a correct estimation remains unclear.Here we propose and experimentally demonstrate a technique that measures a high-dimensional quantum state with the combination of scan-free measurement and direct strong measurement.The procedure involves sequential strong measurement,in which case no approximation is made similarly to the conventional direct weak measurement.We use this method to measure a transverse state of a photon with effective dimensionality of 65000 without the time-consumed scanning process.Furthermore,the high fidelity of the result and the simplicity of the experimental apparatus show that our approach can be readily used to measure the complex field of a beam in diverse applications such as wavefront sensing and quantitative phase imaging.

关 键 词：process. QUANTUM SIMPLICITY 

分 类 号：O413.1[理学—理论物理]