Entanglement between surface-plasmon-polariton modes and its application to long-distance quantum communication

We propose a scheme for achieving quantum entanglement between surface-plasmon-polariton (SPP) modes in a hybrid plasmonic-graphene waveguide system. We then demonstrate that the entanglement of two SPP modes can serve as a useful resource for quantum communication of continuous-variable light signals over a long distance, mediated by concatenated swap operations. The teleportation fidelity of an unknown coherent state has strong robustness to loss and imperfect detection at relatively strong effective optical-microwave coupling. Our study opens the way for continuous-variable quantum communication and quantum information based on hybrid plasmonic-graphene systems.