Communication cost of quantum channels

Yuxiang Yang, Giulio Chiribella, Masahito Hayashi

Published 2020-02-17Version 1

In distributed computing, it is common for a server to execute a program of a remote client, consuming the minimum amount of communication. We extend such a setting to the quantum regime and consider the task of communicating quantum channels for the purpose of executing them a given number of times. We derive a general lower bound for the amount of required communication. The bound shows that the amount of required communication is positively correlated to the performance of the channels in quantum metrology. We also propose a protocol achieving the bound for a type of channels.