The field · networking
Quantum networking
A quantum network moves entanglement, not bits, the resource behind quantum key distribution, distributed sensing, and eventually linking processors. The record below runs from a satellite to a live telecom network; the Bell tests these papers report are the same experiment the arcade's CHSH game lets you sample.
- Verified, published result
- Vendor reported result
- Projection, roadmap target
- Opinion, named, dated
- Estimate, with caveats
- Contested, disputed in the record
- Preprint, not yet peer reviewed
Milestones, by distance and by ingredient
Satellite entanglement over 1,203 km (Micius)
Verified, published resultYin et al. distributed entangled photon pairs from a satellite to two ground stations separated by 1,203 km, the distance record that established space links as a route around fiber loss.
Quantum memory nodes entangled over 35 km of Boston fiber
Verified, published resultKnaut et al. (Harvard/AWS) entangled silicon vacancy centers in nanophotonic diamond cavities, nodes with electron and long lived nuclear spin qubits, across a 35 km fiber loop deployed in the Boston urban environment, plus 40 km spools. Memory nodes, not just photons, are what a repeater network needs.
Entanglement on a live telecom network, alongside classical traffic
Verified, published resultSena et al. ran polarization entangled photons through Deutsche Telekom's Berlin metropolitan fibers over selectable paths from 10 m to 60 km (extended to ~100 km), at 1324 nm coexisting with bidirectional C-band classical traffic on the same fibers. Bell state fidelities of 85-99%, CHSH S between 2.36 and 2.74, and under 1.5% downtime across multi day runs, the same Bell test the arcade lets you run.
8,235 stored modes of entanglement across Geneva
Preprint, not yet peer reviewedRodriguez, Nicolas, Afzelius et al. distributed entanglement over 5.66 km of the Geneva metropolitan network while storing 8,235 temporal modes for 63 µs in a quantum memory (16,340 modes for 125 µs in the lab). Multimode memories are the throughput ingredient a quantum repeater requires. A preprint at the time of checking.
What is not yet built
No quantum repeater network, entanglement distributed over long distance by chaining memory nodes, without trusted intermediate sites, has been deployed at scale as of the check date. The entries above are the components: space links, memory nodes, live fiber coexistence, and multimode storage.