An Elementary Quantum Network of Single Atoms in Optical Cavities

TL;DR

This paper demonstrates a scalable quantum network prototype using single atoms in optical cavities, capable of quantum state transfer and entanglement, advancing the development of large-scale quantum communication systems.

Contribution

It introduces a novel cavity-based quantum network with universal nodes that can transfer and entangle quantum states, showing a clear path toward scalable quantum networks.

Findings

Successful quantum state transfer between nodes

Creation of entanglement in independent laboratories

Potential for scalable quantum network implementation

Abstract

Quantum networks are distributed quantum many-body systems with tailored topology and controlled information exchange. They are the backbone of distributed quantum computing architectures and quantum communication. Here we present a prototype of such a quantum network based on single atoms embedded in optical cavities. We show that atom-cavity systems form universal nodes capable of sending, receiving, storing and releasing photonic quantum information. Quantum connectivity between nodes is achieved in the conceptually most fundamental way: by the coherent exchange of a single photon. We demonstrate the faithful transfer of an atomic quantum state and the creation of entanglement between two identical nodes in independent laboratories. The created nonlocal state is manipulated by local qubit rotation. This efficient cavity-based approach to quantum networking is particularly promising as it offers a clear perspective for scalability, thus paving the way towards large-scale quantum networks and their applications.