Strong Converse for Identification via Quantum Channels

TL;DR

This paper proves a strong converse for identification over quantum channels using a novel covering lemma and large deviation estimates, extending classical methods to quantum information theory.

Contribution

It introduces a new proof technique for quantum channel identification, generalizing classical approaches with explicit large deviation estimates for quantum operators.

Findings

Established a strong converse for quantum identification channels.

Developed a quantum generalization of classical hypergraph covering problems.

Presented a new method based on a covering lemma and large deviation estimates.

Abstract

In this paper we present a simple proof of the strong converse for identification via discrete memoryless quantum channels, based on a novel covering lemma. The new method is a generalization to quantum communication channels of Ahlswede's recently discovered appoach to classical channels. It involves a development of explicit large deviation estimates to the case of random variables taking values in selfadjoint operators on a Hilbert space. This theory is presented separately in an appendix, and we illustrate it by showing its application to quantum generalizations of classical hypergraph covering problems.