Information transmission over an amplitude damping channel with an arbitrary degree of memory

TL;DR

This paper analyzes the classical and quantum capacities of a partially correlated amplitude damping channel with memory, deriving bounds and exploring entanglement's role in optimizing information transmission.

Contribution

It provides new bounds for classical and quantum capacities of channels with memory and investigates entanglement's impact on maximizing information transfer.

Findings

Derived lower bounds for single-shot classical capacity.

Identified entanglement levels involved in maximizing the Holevo quantity.

Computed the entanglement-assisted classical channel capacity.

Abstract

We study the performance of a partially correlated amplitude damping channel acting on two qubits. We derive lower bounds for the single-shot classical capacity by studying two kinds of quantum ensembles, one which allows to maximize the Holevo quantity for the memoryless channel and the other allowing the same task but for the full-memory channel. In these two cases, we also show the amount of entanglement which is involved in achieving the maximum of the Holevo quantity. For the single-shot quantum capacity we discuss both a lower and an upper bound, achieving a good estimate for high values of the channel transmissivity. We finally compute the entanglement-assisted classical channel capacity.