Higher amounts of loophole-free Bell violation using a heralded entangled source

Abstract

Loophole-free Bell non-locality test plays a central role in device-independent quantum information processing tasks, such as device-independent quantum random number generation (QRNG) and quantum key distribution (QKD). Inspired by the scheme of heralded spontaneous parametric down conversion (SPDC) source proposed in (Śliwa C and Banaszek K 2003 Phys. Rev. A 67 030101), we present a loophole-free Bell test scheme that employs the heralded type of entangled photon pairs. Our proposal enables a much higher degree of Bell violation with realistic photonic devices over the one using the conventional SPDC source, thus allowing the implementation of device-independent QRNG and QKD with significant advantages. We anticipate that the scheme will enable variously subtle applications in device-independent quantum information processing tasks.