Delocalized information in quantum networks

TL;DR

This paper explores how delocalized quantum information in networks enhances robustness, security, and flexibility, using entanglement, error correction, and specific quantum states to enable secure and resilient quantum communication.

Contribution

It introduces methods for storing and transmitting quantum information in a delocalized manner within networks, utilizing entanglement and error correction to improve security and fault tolerance.

Findings

Delocalized information offers protection against node failure and decoherence.

Local measurements enable information transmission without full state transfer.

Protocols based on stabilizer codes and Dicke states facilitate network design.

Abstract

We consider entanglement-based quantum networks where information is stored in a delocalized way within regions or the whole network. This offers a natural protection against failure of network nodes, loss and decoherence, and has built-in security features. Quantum information is transmitted within the network by performing local measurements on individual nodes only. Information can be localized within regions or at a specific node by collaborative actions using only entanglement within a region, or sometimes even without entanglement. We discuss several examples based on error correction stabilizer codes, Dicke states and correlation space encodings. We show how to design fully functional networks using encoded states or correlation space resources.