Quantum repeaters free of polarization disturbance and phase noise

TL;DR

This paper proposes a quantum repeater protocol that is immune to both polarization disturbance and phase noise, enabling more reliable long-distance quantum communication using existing cavity-QED and linear optics technologies.

Contribution

It introduces a novel quantum repeater scheme leveraging the invariance of the anti-symmetric Bell state to eliminate channel noise effects.

Findings

Protocol is immune to polarization disturbance and phase noise.

Implementation feasible with current cavity-QED and linear optics technologies.

Enhances long-distance quantum communication reliability.

Abstract

Original quantum repeater protocols based on single-photon interference suffer from phase noise of the channel, which makes the long-distance quantum communication infeasible. Fortunately, two-photon interference type quantum repeaters can be immune to phase noise of the channel. However, this type quantum repeaters may still suffer from polarization disturbance of the channel. Here we propose a quantum repeaters protocol which is free of polarization disturbance of the channel based on the invariance of the anti-symmetric Bell state $|\psi^->=(|H>|V>-|V>|H>)/\sqrt{2}$ under collective noise. Our protocol is also immune to phase noise with the Sagnac interferometer configuration. Through single-atom cavity-QED technology and linear optics, this scheme can be implemented easily.