The classical capacity of quantum channels with memory

Abstract

We investigate the classical capacity of two quantum channels with memory: a periodic channel with depolarizing channel branches, and a convex combination of depolarizing channels. We prove that the capacity is additive in both cases. As a result, the channel capacity is achieved without the use of entangled input states. In the case of a convex combination of depolarizing channels the proof provided can be extended to other quantum channels whose classical capacity has been proved to be additive in the memoryless case.

6 double-column pages. Short note added on quantum memory channels

References in corpus (2)

• Coding Theorem for a Class of Quantum Channels with Long-Term Memory
• Simplification of additivity conjecture in quantum information theory

Cited by in corpus (1)

• Quantum Finite-Depth Memory Channels: Case Study