Measurement-device-independent quantum key distribution with nitrogen vacancy centers in diamond

Nicoló Lo Piparo, Mohsen Razavi, William J. Munro

Published 2016-03-11Version 1

Memory-assisted measurement-device-independent quantum key distribution (MA-MDI-QKD) has recently been proposed as a possible intermediate step towards the realization of quantum repeaters. Despite its relaxing some of the requirements on quantum memories, the choice of memory in relation to the layout of the setup and the protocol has a stark e?ect on our ability to beat existing no-memory systems. Here, a variant of MA-MDI-QKD that relies on nitrogen vacancy (NV) centers as its quantum memories is proposed. We particularly focus on the cavity-enhanced NV centers and show that, in terms of the secret key rate per transmitted pulse, we can beat the existing no-memory QKD systems by up to three orders of magnitude. Using system parameters achievable by the today's state of the art, we then anticipate some total key rate advantage in the distance range between 300 km and 500 km. Our analysis accounts for major sources of error including the dark current, the channel loss, and the decoherence of the quantum memories.