Identification Over Quantum Broadcast Channels

TL;DR

This paper explores quantum broadcast channels focusing on identification rather than transmission, deriving capacity regions and demonstrating improvements over previous bounds for specific quantum channels.

Contribution

It provides a new achievable identification region for quantum broadcast channels and a full characterization for classical-quantum channels, including the quantum erasure broadcast channel.

Findings

Derived an achievable identification region for quantum broadcast channels.

Full characterization of the identification capacity region for classical-quantum broadcast channels.

Improved bounds for the quantum erasure broadcast channel.

Abstract

Identification over quantum broadcast channels is considered. As opposed to the information transmission task, the decoder only identifies whether a message of his choosing was sent or not. This relaxation allows for a double-exponential code size. An achievable identification region is derived for a quantum broadcast channel, and a full characterization for the class of classical-quantum broadcast channels. The identification capacity region of the single-mode pure-loss bosonic broadcast channel is obtained as a consequence. Furthermore, the results are demonstrated for the quantum erasure broadcast channel, where our region is suboptimal, but improves on the best previously known bounds.