Quantum repeaters for communication

TL;DR

This paper proposes a quantum repeater scheme that uses nested purification protocols to connect entangled pairs, overcoming exponential error scaling in noisy quantum communication channels.

Contribution

It introduces a novel nested purification protocol enabling high-fidelity entanglement over long distances, tolerating general errors at the percent level.

Findings

The scheme effectively overcomes exponential error scaling.

It tolerates errors at the percent level.

High-fidelity entanglement can be established over long distances.

Abstract

In quantum communication via noisy channels, the error probability scales exponentially with the length of the channel. We present a scheme of a quantum repeater that overcomes this limitation. The central idea is to connect a string of (imperfect) entangled pairs of particles by using a novel nested purification protocol, thereby creating a single distant pair of high fidelity. The scheme tolerates general errors on the percent level.