Efficient bounds on quantum communication rates via their reduced variants

TL;DR

This paper introduces reduced variants of quantum communication rates and establishes new upper bounds on key quantities like secret key and channel capacity, improving estimation accuracy in one-way quantum communication scenarios.

Contribution

It defines reduced quantum communication rates and proves bounds that significantly enhance estimation of quantum communication capacities.

Findings

Reduced variants provide tighter bounds on quantum communication measures

New upper bounds improve estimation accuracy in one-way scenarios

In some cases, bounds drastically outperform previous estimates

Abstract

We investigate one-way communication scenarios where Bob manipulating on his parts can transfer some sub-system to the environment. We define reduced versions of quantum communication rates and further, prove new upper bounds on one-way quantum secret key, distillable entanglement and quantum channel capacity by means of their reduced versions. It is shown that in some cases they drastically improve their estimation.