Experimental multipartite entanglement and randomness certification of the W state in the quantum steering scenario
A Máttar, Paul Skrzypczyk, G H Aguilar, R V Nery, P H Souto Ribeiro, Stephen Patrick Walborn, D Cavalcanti · Quantum Science and Technology · 2017
Abstract Recently, Cavalcanti et al (2015) proposed a method to certify the presence of entanglement in asymmetric networks, where some users do not have control over the measurements they are performing. Such asymmetry naturally emerges in realistic situations, such as in cryptographic protocols over quantum networks. Here we implement such ‘semi-device-independent’ techniques to experimentally witness all types of entanglement on a three-qubit photonic W state. Furthermore, we analyse the amount of genuine randomness that can be certified in this scenario from any bipartition of the three-qubit W state.