Quantum Nonlocality of Single Photon State?

Dipankar Home, G. S. Agarwal

Su‐Yong Lee, Jiyong Park, Jaewan Kim +1 more

Paolo Abiuso, Tamás Kriváchy, Emanuel-Cristian Boghiu +3 more

The state obtained when a single photon impinges on a balanced beamsplitter is often known as single-photon entangled and its nonlocal properties have been the subject of intense debates in the quantum optics and foundations communities. It is however clear that a standard Bell test made only of passive optical elements cannot reveal the nonlocality of this state. We show that the nonlocality of single-photon entangled states can nevertheless be revealed in a quantum network made only of beamsplitters and photodetectors. In our protocol, three single-photon entangled states are distributed in a triangle network, introducing indeterminacy in the photons' paths and creating nonlocal correlations without the need for measurements choices. We discuss a concrete experimental realisation and provide numerical evidence of the tolerance of our protocol to standard noise sources. Our results show that single-photon entanglement may constitute a promising solution to generate genuine network-nonlocal correlations useful for Bell-based quantum information protocols.

Aurélien Drezet

Paolo Abiuso, Tamás Kriváchy, Emanuel-Cristian Boghiu +3 more

A single-photon maximally entangled state is obtained when a photon impinges on a balanced beamsplitter.Its nonlocal properties have been intensively debated in the quantum optics and foundations communities.It is however clear that a standard Bell test made only of passive optical elements cannot reveal the nonlocality of this state.We show that the nonlocality of single-photon entangled states can nevertheless be revealed in a quantum network made only of beamsplitters and photodetectors.In our protocol, three single-photon entangled states are distributed in a triangle network, introducing indeterminacy in the photons' paths and creating nonlocal correlations without the need for measurements choices.We discuss a concrete experimental realization and provide numerical evidence of the tolerance of our protocol to standard noise sources.Our results show that single-photon entanglement may constitute a promising solution to generate genuine network-nonlocal correlations useful for Bell-based quantum information protocols.

M. Ardehali