We report an experimental realisation of a quantum random number generator using a plasmonic beamsplitter. Free-space single photons are converted into propagating single surface plasmon polaritons on a gold stripe waveguide via a grating. The surface plasmons are then guided to a region where they are scattered into one of two possible outputs. The presence of a plasmonic excitation in a given output determines the value of a random bit generated from the quantum scattering process. Using a stream of single surface plasmons injected into the beamsplitter we achieve a quantum random number generation rate of 2.37 Mbits/s even in the presence of loss. We characterise the quality of the random number sequence generated, finding it to be comparable to sequences from other quantum photonic-based devices. The compact nature of our nanophotonic device makes it suitable for tight integration in on-chip applications, such as in quantum computing and communication schemes.
@article{arxiv.1610.06300,
title = {Quantum random number generation using an on-chip plasmonic beamsplitter},
author = {Jason Francis and Xia Zhang and Şahin K. Özdemir and Mark Tame},
journal= {arXiv preprint arXiv:1610.06300},
year = {2017}
}