Quantum state sharing with continuous variables

Quantum state sharing is an important quantum information protocol that deals with a secret quantum state distributed among a group of players, certain subsets of which can access the state while other subsets cannot get any information about it. Continuous-variable quantum state sharing uses light to carry the quantum information and linear optics for the state distribution and extraction, and has been realized experimentally for three players, any two of which are authorized to extract the secret state. The experimentally achieved fidelity of quantum state sharing exceeds the fidelity accessible without quantum resources, which puts the experimental realization well within the quantum domain. Quantum state sharing can be combined into complex quantum information protocols and can be expected to become an important part of full-scale quantum information processing protocols with continuous variables.