Capacity Theorems for Quantum Multiple Access Channels

TL;DR

This paper establishes capacity theorems for quantum multiple access channels, providing multi-letter characterizations of different information transmission scenarios involving classical and quantum data.

Contribution

It introduces multi-letter capacity region characterizations for quantum multiple access channels with two senders, including special cases with single-letter descriptions.

Findings

Multi-letter capacity regions for classical-quantum and quantum-quantum communication.

Single-letter capacity descriptions for specific channels.

Characterization of simultaneous classical and quantum information transmission rates.

Abstract

We consider quantum channels with two senders and one receiver. For an arbitrary such channel, we give multi-letter characterizations of two different two-dimensional capacity regions. The first region characterizes the rates at which it is possible for one sender to send classical information while the other sends quantum information. The second region gives the rates at which each sender can send quantum information. We give an example of a channel for which each region has a single-letter description, concluding with a characterization of the rates at which each user can simultaneously send classical and quantum information.