On Reliability Function of Quantum Communication Channel

Abstract

The reliability function gives the rate of exponential convergence to zero of the error probability in a communication channel. In this paper bounds for the reliability function of a quantum pure state channel are given, reminiscent of the corresponding classical bounds. This in particular suggests an alternative proof of the coding theorem for quantum noiseless channel, which would make no use of the notion of typical subspace. Example of binary quantum channel is considered in some detail.