Experimental quantum triangle network nonlocality with an AlGaAs multiplexed entangled photon source

TL;DR

This paper demonstrates experimental quantum nonlocality in a triangle network using an AlGaAs multiplexed entangled photon source, revealing new correlations without inputs and advancing quantum communication applications.

Contribution

First experimental realization of quantum triangle network nonlocality with correlated sources engineered from a multiplexed AlGaAs photon source, including violation of a derived Bell-like inequality.

Findings

Successfully violated a Bell-like inequality in a quantum triangle network.

Engineered correlated photon sources with minimal independence.

Analyzed mutual information to validate nonlocal correlations.

Abstract

The exploration of the concept of nonlocality beyond standard Bell scenarios in quantum network architectures unveils fundamentally new forms of correlations that hold a strong potential for future applications of quantum communication networks. To materialize this potential, it is necessary to adapt theoretical advances to realistic configurations. Here we consider a quantum triangle network, for which is was shown in theory that, remarkably, quantum nonlocality without inputs can be demonstrated for sources with an arbitrarily small level of independence. We realize experimentally such correlated sources by carefully engineering the output state of a single AlGaAs multiplexed entangled-photon source, exploiting energy-matched channels cut in its broad spectrum. This simulated triangle network is then used to violate experimentally for the first time a Bell-like inequality that we derive to capture the effect of noise in the correlations present in our system. We also rigorously validate our findings by analysing the mutual information between the generated states. Our results allow us to deepen our understanding of network nonlocality while also pushing its practical relevance for quantum communication networks.