EPB Quantum Network — Chattanooga
A customer-configurable, entanglement-based quantum network running on dark fibre owned by Chattanooga's municipal utility. Launched in 2022 as the first commercially-available quantum network in the United States, opened to paid customers in 2023, and extended in 2025 with an IonQ trapped-ion processor placed directly on the network to add a quantum-compute endpoint to the testbed.
What it is
The network sits on dark fibre EPB originally built between its electric substations, repurposed under a 2021 collaboration with Qubitekk, Oak Ridge National Laboratory, and Los Alamos National Laboratory. Qubitekk supplies the quantum hardware — entangled-photon sources, single-photon detectors, and the Bohr IV quantum-networking system that generates, transmits, and measures qubits across the loop. EPB 2022 (launch press) Aliro Quantum's AliroNet was selected as the network controller in February 2023; it provides multi-tenant role-based access, network design and emulation modes, and the operations layer that lets a customer specify a configuration and have the underlying optical switches and devices provisioned to match. EPB/Aliro 2023 (controller press) Aliro 2024 (deployments WP)
The deployed topology is a network operations centre plus two equipment hubs, each carrying eleven quantum devices, that fan out to ten quantum nodes across the loop — over thirty quantum devices in total. AliroNet's multi-tenant role-based access control is what lets different customer organisations share that fabric without seeing each other's experiments. Aliro 2024 (deployments WP)
Qunnect became the first announced commercial customer in December 2023, bringing its QU-APC automatic polarisation controller for interoperability testing against Qubitekk's entangled-photon source. The teams reported entanglement preservation with fidelity above 99 % during the December 4–6 2023 run — the first time Qunnect's QU-APC had been tested on a commercial quantum network outside its own GothamQ testbed in New York. EPB/Qunnect 2023 (interop press) ORNL ran the first national-laboratory experiment on the network in 2024, validating it as a research surface as well as a vendor interop bench. ORNL/EPB 2024 (first ORNL run)
In April 2025 the EPB board approved a $22 million deal with IonQ to place an IonQ Forte Enterprise trapped-ion system on the network and stand up the EPB Quantum Center. Build-out and commissioning were scheduled for completion by early 2026. EPB/IonQ 2025 (Quantum Center press) IonQ 2025 (EPB deal press) The arrangement makes EPB the first utility company to commercially offer both quantum networking and quantum compute, with IonQ opening a Chattanooga office to support customer onboarding.
Verified claims
- Announced 2022 as the first commercially available quantum network in the US. EPB's own launch press uses "America's first commercially available quantum network"; IEEE Spectrum, ORNL, and Aliro corroborate. The "world's first user-configurable, commercial-grade" wording often quoted is the vendor framing — the verifiable claim is "first commercially available in the US". EPB 2022 (launch press)
- Entanglement-based, not a QKD trunk. Aliro's real-world-deployments white paper and EPB's own project page describe the network as a "reconfigurable fiber testbed for entangled photons". Qubitekk supplies the entangled-photon sources and detectors; the December 2023 interop with Qunnect explicitly measured entanglement-preservation fidelity. Aliro 2024 (deployments WP) EPB/Qunnect 2023 (interop press)
- Aliro is the network OS / controller; Qubitekk is the hardware vendor; EPB owns the fibre. Confirmed by the February 2023 controller-selection press release. EPB/Aliro 2023 (controller press)
- Paid testbed, not a data-replacement network. EPB markets the offering as quantum-as-a-service: customers reserve configurations and run experiments on the loop. It is not a replacement for classical internet or backbone traffic — no user data flows through it. EPB 2022 (launch press) Aliro 2024 (deployments WP)
- April 2025 IonQ deal — $22 million, trapped-ion node on the network. Joint EPB / IonQ press, 25 April 2025; the machine is an IonQ Forte Enterprise (#AQ36); build-out by early 2026. EPB/IonQ 2025 (Quantum Center press) IonQ 2025 (EPB deal press)
- Chattanooga differentiator vs the Chinese QKD trunk. The Beijing–Shanghai backbone uses polarisation-coded decoy-state BB84 with weak coherent pulses through 32 trusted relays — prepare-and-measure with key reconstruction at each hop. EPB distributes entangled photon pairs end-to-end through the loop, so it supports protocols beyond key distribution (entanglement swapping demos, distributed sensing, blind compute experiments). See the Beijing–Shanghai case study for the contrast.
Things to note
- Scope. The deployment is a single-operator metro loop on which customers run experiments. It does not provide inter-domain routing, public addressing, or standing user-data traffic.
- Service model. The infrastructure can host QKD experiments, and the primary product is shared access to an entanglement-distribution testbed. The BT/Toshiba London commercial QKD trial (also 2022) is a separate category of deployment.
- What "user-configurable" covers. AliroNet provisions network topology, paths, and access policy at the optical layer; the photonic protocol that runs on top is supplied by the customer's hardware.
- IonQ integration status. The 2025 press described placing IonQ Forte Enterprise on the network as part of a combined compute + networking offering, with build-out continuing into 2026. The network and the trapped-ion processor are co-located inside the same facility; the coupling between the trapped-ion qubits and the entanglement layer is a 2026 deliverable. EPB/IonQ 2025 (Quantum Center press)
- Scope of the R&D 100 award. The award refers to the underlying Qubitekk technology and the prior EPB/ORNL/LANL field trial, rather than to a third-party rating of the commercial network itself.