Photonic realization of erasure-based nonlocal measurements

Nanophotonics

article

Wei-Wei Pan¹  Guang-Can Guo¹  Xiao-Ye Xu¹  Eliahu Cohen³  Qin-Qin Wang¹  Zhe Chen¹  Munsif Jan¹  Yong-Jian Han¹  Chuan-Feng Li² 

[1] CAS Key Laboratory of Quantum Information, University of Science and Technology of China;CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China;Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar Ilan University

关键词: quantum optics;    quantum information;    quantum gates;    quantum erasure;    nonlocal measurements;   

DOI  :  10.1515/nanoph-2019-0089

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Relativity theory severely restricts the ability to perform nonlocal measurements in quantum mechanics. Studying such nonlocal schemes may thus reveal insights regarding the relations between these two fundamental theories. Therefore, for the last several decades, nonlocal measurements have stimulated considerable interest. However, the experimental implementation of nonlocal measurements imposes profound restrictions because the interaction Hamiltonian cannot contain, in general, nonlocal observables such as the product of local observables belonging to different particles at spacelike-separated regions. In this work, we experimentally realize a scheme for nonlocal measurements with the aid of probabilistic quantum erasure. We apply this scheme to the tasks of performing high-accuracy nonlocal measurements of the parity, as well as measurements in the Bell basis, which do not necessitate classical communication between the parties. Unlike other techniques, the nonlocal measurement outcomes are available locally (upon successful postselection). The state reconstructed via performing quantum tomography on the system after the nonlocal measurement indicates the success of the scheme in retrieving nonlocal information while erasing any local data previously acquired by the parties. This measurement scheme allows to realize any controlled-controlled-gate with any coupling strength. Hence, our results are expected to have conceptual and practical applications to quantum communication and quantum computation.

【 授权许可】

CC BY