Polaractivation of Hidden Private Classical Capacity Region of Quantum Channels

TL;DR

This paper introduces polaractivation, a quantum polar encoding technique that reveals hidden private classical capacity regions in noisy quantum channels by exploiting channel polarization effects.

Contribution

It presents the concept of polaractivation for quantum channels, demonstrating how to open hidden capacity regions and providing criteria and bounds for its application.

Findings

Polaractivation enables access to previously unreachable private capacity regions.

The method applies to arbitrary quantum channels under certain capacity criteria.

A lower bound on classical communication rate for polaractivation is derived.

Abstract

We define a new phenomenon for communication over noisy quantum channels. The investigated solution is called polaractivation and based on quantum polar encoding. Polaractivation is a natural consequence of the channel polarization effect in quantum systems and makes possible to open the hidden capacity regions of a noisy quantum channel by using the idea of rate increment. While in case of a classical channel only the rate of classical communication can be increased, in case of a quantum channel the channel polarization and the rate improvement can be exploited to open unreachable capacity regions. We demonstrate the results for the opening of private classical capacity-domain. We prove that the method works for arbitrary quantum channels if a given criteria in the symmetric classical capacity is satisfied. We also derived a necessary lower bound on the rate of classical communication for the polaractivation of private classical capacity-domain.