Semi-device-independent certification of indefinite causal order in a photonic quantum switch

Autor(en)

Huan Cao, Jessica Bavaresco, Ning Ning Wang, Lee A. Rozema, Chao Zhang, Yun Feng Huang, Bi Heng Liu, Chuan Feng Li, Guang Can Guo, Philip Walther

Abstrakt

Quantum processes are transformations that act on quantum operations. Their study led to the discovery of the phenomenon of indefinite causal order: some quantum processes, such as the quantum switch, act on independent quantum operations in such a way that the order in which the operations are acted upon not only cannot be determined but is simply undefined. This is the property that we experimentally certify in this work. We report an experimental certification of indefinite causal order that relies only on the characterization of the operations of a single party. We do so in the semi-device-independent scenario with the fewest possible assumptions of characterization of the parties’ local operations in which indefinite causal order can be demonstrated with the quantum switch. To achieve this result, we introduce the concept of semi-device-independent causal inequalities and show that the correlations generated in a photonic quantum switch, in which all parties are able to collect local outcome statistics, achieve a violation of this inequality of 224 standard deviations. This result consists of the experimental demonstration of indefinite causal order with the fewest device-characterization assumptions to date.

Organisation(en)

Quantenoptik, Quantennanophysik und Quanteninformation, Forschungsverbund Quantum Aspects of Space Time

Externe Organisation(en)

Österreichische Akademie der Wissenschaften (ÖAW), Universität Genf, University of Science and Technology of China (USTC)

Journal

Optica

Band

10

Seiten

561-568

Anzahl der Seiten

8

ISSN

2334-2536

DOI

https://doi.org/10.1364/OPTICA.483876

Publikationsdatum

05-2023

Peer-reviewed

Ja

ÖFOS 2012

103025 Quantenmechanik

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Atomic and Molecular Physics, and Optics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/a310bf6c-6d15-4148-8d34-0058004b7ec5