Perfect Quantum Network Communication Protocol Based on Classical Network Coding

Understand

This paper considers a problem of quantum communication between parties that are connected through a network of quantum channels.

• The model in this paper assumes that there is no prior entanglement shared among any of the parties, but that classical communication is free.
• The task is to perfectly transfer an unknown quantum state from a source subsystem to a target subsystem, where both source and target are formed by ordered sets of some of the nodes.
• It is proved that a lower bound of the rate at which this quantum communication task is possible is given by the classical min-cut max-flow theorem of network coding, where the capacities in question are the quantum capacities of the edges of the network.