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Experimental violation of local causality in a quantum network.
Gonzalo Carvacho1, Francesco Andreoli1, Luca Santodonato1
1Dipartimento di Fisica - Sapienza Università di Roma, P.le Aldo Moro 5, I-00185 Roma, Italy.
Nature Communications
|March 17, 2017
Summary
This study demonstrates non-bilocal quantum correlations in a three-node network, violating a Bell-like inequality. The findings advance quantum networks and communication protocols by exploring correlations mediated by multiple sources.
Area of Science:
- Quantum Information Science
- Quantum Communication Networks
- Foundations of Quantum Mechanics
Background:
- Bell's theorem is fundamental to quantum information processing.
- Previous experiments on Bell inequality violations did not account for multiple independent sources mediating correlations in quantum networks.
Purpose of the Study:
- To investigate quantum correlations in a network with three spatially separated nodes and two distinct sources.
- To experimentally demonstrate non-bilocal correlations, which are incompatible with local models using independent hidden variables.
Main Methods:
- Utilized a photonic setup to create a quantum network.
- Investigated correlations mediated by two independent sources between three nodes.
- Violated a Bell-like inequality under the fair-sampling assumption.
Main Results:
- Successfully demonstrated the emergence of non-bilocal correlations.
- Provided experimental evidence for the violation of a Bell-like inequality in a multi-source network scenario.
Conclusions:
- The experiment serves as a proof-of-principle for generalized Bell's theorem in networks.
- The demonstrated non-bilocal correlations could be a valuable resource for future quantum communication protocols.
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