Improving the maximum transmission distance of continuous-variable quantum key distribution using a noiseless amplifier

Rémi Blandino (1) , Anthony Leverrier (2, 1) , Marco Barbieri (1) , Jean Etesse (1) , Philippe Grangier (1) , Rosa Tualle-Brouri (1)

1 Laboratoire Charles Fabry / Optique Quantique
2 The Institute of Photonic Sciences

We show that the maximum transmission distance of continuous-variable quantum key distribution in presence of a Gaussian noisy lossy channel can be arbitrarily increased using a linear noiseless amplifier. We explicitly consider a protocol using amplitude and phase modulated coherent states with reverse reconciliation. We find that a noiseless amplifier with amplitude gain g can increase the maximum admissible losses by a factor 1/g^2.

Domaines: Physique Quantique [quant-ph]; Optique [physics.optics]

Rémi Blandino, Anthony Leverrier, Marco Barbieri, Jean Etesse, Philippe Grangier, et al.. Improving the maximum transmission distance of continuous-variable quantum key distribution using a noiseless amplifier. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2012, 86 (1), pp.012327. ⟨10.1103/PhysRevA.86.012327⟩. ⟨hal-00749512⟩