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Quantum Information and Measurement (QIM)

Heralded Photon Amplification for Path Entangled Quantum Communication

F. Monteiro, E. Verbanis, Valentina Caprara Vivoli, Anthony Martin, Nicolas Gisin, Hugo Zbinden, Rob Thew

Published Jan 1, 2017• 4 citations
Publisher

Abstract

We experimentally studied heralded photon amplification for path entangled states and characterise entanglement before and after loss by exploiting displacement-based measurements. We demonstrate the recovery of high fidelity entangled states over loss-equivalent distances > 50km.
DOI
10.1364/qim.2017.qf3b.3

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Abstract Device-independent quantum key distribution (DI-QKD) represents one of the most fascinating challenges in quantum communication, exploiting concepts of fundamental physics, namely Bell tests of nonlocality, to ensure the security of a communication link. This requires the loophole-free violation of a Bell inequality, which is intrinsically difficult due to losses in fibre optic transmission channels. Heralded photon amplification (HPA) is a teleportation-based protocol that has been proposed as a means to overcome transmission loss for DI-QKD. Here we demonstrate HPA for path entangled states and characterise the entanglement before and after loss by exploiting a recently developed displacement-based detection scheme. We demonstrate that by exploiting HPA we are able to reliably maintain high fidelity entangled states over loss-equivalent distances of more than 50 km.
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