IonQ (NYSE: IONQ) has secured a contract with the Defense Advanced Research Projects Agency (DARPA) as part of the Heterogeneous Architectures for Quantum (HARQ) program. This initiative focuses on the development of networked quantum architectures that integrate diverse qubit modalities—such as trapped ions, neutral atoms, and superconducting qubits—into a unified, high-performance system. The program seeks to utilize the technical strengths of each modality while leveraging advancements in photonic integration to enable reliable communication between different qubit species.

Simultaneously, IonQ has achieved a foundational technical milestone by photonically interconnecting two independent trapped-ion quantum systems. This demonstration, conducted in collaboration with the Air Force Research Laboratory (AFRL), marks the first time two commercial quantum computers have been networked via quantum entanglement at a distance. The achievement validates the generation, transmission, and detection of photons required to link separate processors while maintaining the quantum coherence necessary for distributed computational operations.

IonQ’s contribution to the HARQ program centers on the development of specialized quantum memories fabricated from quantum-grade synthetic diamond. These memories serve as the core components for the company’s interconnect systems and are designed to meet DARPA’s high-speed and high-fidelity targets for long-distance entanglement distribution. This work builds upon IonQ’s 2025 milestone of achieving the first qubit-to-photon frequency conversion in a field-deployable system, which allows quantum networks to operate over standard commercial fiber-optic infrastructure.

The program includes 19 performer teams from 15 organizations working across two specialized workstreams.

  • The MOSAIC (Multi-qubit Optimized Software Architecture through Interconnected Compilation) stream focuses on software frameworks and compilers to optimize performance across diverse qubit types, with participants including Infleqtion, memQ, Q-CTRL, and the Universities of Michigan and Pennsylvania.
  • The Quantum Shared Backbone (QSB) stream, which focuses on the hardware required for cross-platform communication, includes IonQ, Harvard, Stanford, UC Berkeley, the Australian National University, and EPFL, alongside other academic partners.

The successful demonstration of networked “network qubits” provides a technical path for scaling system capacity beyond the physical constraints of a single chip. By transitioning toward modular architectures, IonQ aims to support the development of a distributed quantum internet and fault-tolerant systems. CEO Niccolo de Masi noted that the trapped-ion platform is particularly suited for the high-fidelity networking required to solve complex problems, as distributed systems can effectively bypass the engineering challenges of building massive monolithic processors.

These technical advancements follow a period of increased collaboration between IonQ and federal defense partners, including its progression to Stage B of DARPA’s quantum benchmarking initiative. With its IonQ Tempo system having reached the #AQ 64 milestone and the company maintaining a world-record 99.99% two-qubit gate fidelity, the integration of photonic interconnects and heterogeneous networking protocols is intended to provide the infrastructure necessary for both advanced public and private sector applications.

Official announcements regarding the DARPA HARQ selection are available here, and details on the photonic interconnect milestone can be found here.

April 14, 2026

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