Realization of a multi-node quantum network of remote solid-state qubits

TL;DR

This paper reports the experimental realization of a scalable three-node quantum network using solid-state qubits, enabling real-time communication, entanglement distribution, and quantum protocols without post-selection.

Contribution

It demonstrates a multi-node quantum network with remote solid-state qubits, real-time operations, and implementation of key quantum protocols, advancing quantum internet technology.

Findings

Successful creation of a three-node entangled quantum network

Real-time feed-forward gate operations achieved

Distribution of multipartite entangled states without post-selection

Abstract

The distribution of entangled states across the nodes of a future quantum internet will unlock fundamentally new technologies. Here we report on the experimental realization of a three-node entanglement-based quantum network. We combine remote quantum nodes based on diamond communication qubits into a scalable phase-stabilized architecture, supplemented with a robust memory qubit and local quantum logic. In addition, we achieve real-time communication and feed-forward gate operations across the network. We capitalize on the novel capabilities of this network to realize two canonical protocols without post-selection: the distribution of genuine multipartite entangled states across the three nodes and entanglement swapping through an intermediary node. Our work establishes a key platform for exploring, testing and developing multi-node quantum network protocols and a quantum network control stack.