Heralded amplification of path entangled quantum states. (31st May 2017)

• Record Type: Journal Article
• Authors: Monteiro, F; Verbanis, E; Vivoli, V Caprara; Martin, A; Gisin, N; Zbinden, H; Thew, R T
• Is Part Of: Quantum science and technology. Volume 2:Number 2(2017)
• Publication Date: 2017-05-31
• Subjects: quantum communication -- heralded photon amplifier -- path entanglement -- device-independent QKD; Quantum theory -- Periodicals; Quantum theory; Periodicals; 530
• DOI: 10.1088/2058-9565/aa70ad
• Languages: English
• ISSNs: 2058-9565

Abstract

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.