Time-correlated quantum amplitude-damping channel

Abstract

We analyze the problem of sending classical information through qubit channels where successive uses of the channel are correlated. This work extends the analysis of Macchiavello and Palma to the case of a non-Pauli channel---the amplitude damping channel. Using the channel description outlined by Daffer et al., we derive the correlated amplitude damping channel. We obtain a result similar to that obtained by Macchiavello and Palma, that is, under certain conditions on the degree of channel memory, the use of entangled input signals may enhance the information transmission compared to the use of product input signals.