Experimental demonstration of continuous-variable quantum key distribution over 80 km of standard telecom fiber

Continuous-variable quantum key distribution (CVQKD) [1] is a promising alternative to commonly used discrete-variable QKD protocols, because this technology can be implemented with standard telecom components and recent results suggest that it will be compatible with standard wavelength division multiplexed telecommunication networks [2]. Security proofs against general eavesdropping attacks are available for CVQKD protocols using Gaussian modulation [3], and field implementations over deployed telecommunication networks have been demonstrated over the past few years [4].