Pilot Quantum Error Correction for Global-Scale Quantum Communications

TL;DR

This paper introduces a novel quantum error correction method tailored for space-earth quantum communication channels, effectively addressing polarization errors with reduced complexity and achieving capacity in slightly depolarizing channels.

Contribution

The paper presents a new quantum error correction technique specifically designed for space-earth channels, overcoming limitations of existing methods in polarization error correction.

Findings

Effective correction of polarization errors in space-earth channels

Capacity-achieving performance over depolarizing channels

Reduced computational and physical complexity compared to traditional methods

Abstract

Real global-scale quantum communications and quantum key distribution systems cannot be implemented by the current fiber and free-space links. These links have high attenuation, low polarization-preserving capability or extreme sensitivity to the environment. A potential solution to the problem is the space-earth quantum channels. These channels have no absorption since the signal states are propagated in empty space, however a small fraction of these channels is in the atmosphere, which causes slight depolarizing effect. Furthermore, the relative motion of the ground station and the satellite causes a rotation in the polarization of the quantum states. In the current approaches to compensate for these types of polarization errors, high computational costs and extra physical apparatuses are required. Here we introduce a novel approach which breaks with the traditional views of currently developed quantum-error correction schemes. The proposed quantum error-correction technique can be applied to fix the polarization errors which are critical in space-earth quantum communication systems. Moreover, the channel coding scheme provides capacity-achieving communication over slightly depolarizing space-earth channels.