文献类型：期刊文献

英文题名：Sequential device-independent certification of indefinite causal order

作者：Cao, Zhu[1]

机构：[1]East China Univ Sci & Technol, Key Lab Smart Mfg Energy Chem Proc, Minist Educ, Shanghai 200237, Peoples R China

年份：2023

卷号：108

期号：1

外文期刊名：PHYSICAL REVIEW A

收录：;EI(收录号：20230255966);WOS:【SCI-EXPANDED(收录号:WOS:001052288100007)】；

基金：This work was supported by the National Natural Science Foundation of China (Basic Science Center Program 61988101) , the National Natural Science Foundation of China (12105105) , the Natural Science Foundation of Shanghai (21ZR1415800) , the Shanghai Sailing Program (21YF1409800) , the startup fund from East China University of Science and Technology (YH0142214) and the Shanghai AI Lab.

语种：英文

外文关键词：Quantum computers - Quantum optics

摘要：Indefinite causal order has found numerous applications in quantum computation, quantum communication, and quantum metrology. Before its usage, the quality of the indefinite causal order needs to be first certified, and the certification should ideally be device independent (DI) to avoid the impact of device imperfections. In this work, we initiate the study of the sequential DI certification of an indefinite causal order. This can be useful in experimental platforms where the generation of an indefinite causal order is difficult. We show that an arbitrary number of sequential DI certifications of an indefinite causal order can be achieved with a quantum switch and also analyze practical requirements for experimental implementations of the certifications. Our work opens the possibility of reusing the resource of an indefinite causal order multiple times in device-independent quantum information processing.