Ultrafast Long-Distance Quantum Communication with Static Linear Optics

TL;DR

This paper introduces a static linear optical setup for efficient, long-distance quantum communication and quantum computation, leveraging encoded Bell states and error correction to enhance performance and robustness.

Contribution

It presents a novel static linear optical scheme for high-efficiency Bell measurements and quantum communication, enabling scalable, loss-tolerant quantum networks and computation.

Findings

Bell measurement efficiency increases with code size

Quantum communication rates approach classical levels

Loss tolerance can be improved with error correction

Abstract

We propose a projection measurement onto encoded Bell states with a static network of linear optical elements. By increasing the size of the quantum error correction code, both Bell measurement efficiency and photon-loss tolerance can be made arbitrarily high at the same time. As a main application, we show that all-optical quantum communication over large distances with communication rates similar to those of classical communication is possible solely based on local state teleportations using optical sources of encoded Bell states, fixed arrays of beam splitters, and photon detectors. As another application, generalizing state teleportation to gate teleportation for quantum computation, we find that in order to achieve universality the intrinsic loss tolerance must be sacrificed and a minimal amount of feedforward has to be added.