Deep Dive Series

How to Build a Quantum Computer

You can now build a working quantum computer from commercially available vendor components. In March 2026, the Q-PAC consortium in Denver went from concept to cloud-accessible operation in five months, using a QuantWare QPU, Qblox control electronics, a Maybell cryostat, and Q-CTRL calibration software, all assembled by an independent integration team. Similar multi-vendor builds are running at QuTech in Delft and IQM at LRZ in Munich. QuantWare’s $178 million Series B and the construction of KiloFab, a dedicated quantum fabrication facility, confirm that modular quantum computing is no longer an experiment. But the engineering to make it work is anything but simple.

This Deep Dive series is the practical companion to my coverage of quantum computing supply chains and Quantum Open Architecture. Where the supply chain series maps who makes the components and the QOA series explains why modular architecture matters, this series covers what happens when you actually try to integrate them: the facility preparation that most data centers cannot accommodate, the signal chain engineering that determines whether your qubits perform to spec, and the calibration sequences that separate a working machine from an expensive refrigerator full of noise. Each major qubit modality gets a dedicated build guide (superconducting, trapped-ion, neutral-atom, photonic, and silicon-spin), and cross-cutting articles cover the cryogenic infrastructure and helium-3 supply chain, the HPC integration and software stack, and the economics of building and operating at every scale.

The analysis in this series draws on Applied Quantum’s Systems Integration Playbook, the most detailed technical reference for assembling quantum computers from modular components, supplemented by published deployment data from Q-PAC, the IQM/LRZ integration (arXiv:2509.12949), and the QuTech HectoQubit/2 project. For the physics of how each qubit modality works, see the Quantum Computing Modalities Deep Dive.

 

Related Deep Dives

What It Takes to Build a Quantum Computer maps the hidden supply chains behind every modality: who makes the dilution refrigerators, the laser systems, the control electronics, the cabling, and the QPU chips. The parts list you need before integration begins.

Quantum Systems Integration & QOA covers the architecture philosophy and engineering discipline of Quantum Open Architecture: why the industry is moving from monoliths to modules, and what systems integration means in a quantum context.

Quantum Computing Modalities is a field guide to every way humanity is building quantum computers: the physics, the engineering trade-offs, the state of the art, and the realistic path toward fault tolerance for each approach.

Applied Quantum: Systems Integration Services

My company Applied Quantum operates as the independent systems integrator in the Quantum Open Architecture ecosystem, managing multi-vendor interface engineering across cryogenics, microwave signal chains, control electronics, calibration, and HPC integration.

  • Building a Quantum Computer From Components
    Marin IvezicMay 23, 2026

    You Can Now Build a Quantum Computer from Off-the-Shelf Components

    In March 2026, a consortium in Denver assembled a working quantum computer from five different vendors' components in five months. A Dutch QPU, Dutch control electronics, an American cryostat, Australian calibration software, supply chain spanning three continents, integration in Colorado. Three other multi-vendor builds in Delft, Munich, and Naples confirm the pattern. QuantWare's $178 million Series B is funding a 20x production capacity expansion. The Quantum Open Architecture model has moved from conference slides to commercial reality. But the engineering between "we bought the components" and "we have a working quantum computer" is where most organizations underestimate the difficulty. The hard problems are not physics. They are cryogenic systems operating 150 times colder than deep space, a helium-3 supply chain in structural deficit, a cryogenic wiring wall that defines the scaling ceiling more directly than any QPU roadmap, facility requirements that no conventional data center meets, and a real-time error correction pipeline that requires dedicated GPU infrastructure to function. This ten-article series covers the full integration challenge across every major qubit modality: the superconducting build from signal chain engineering through calibration to the troubleshooting data that no one else publishes; the trapped-ion build where the challenge shifts from cryogenics to precision lasers and ultra-high vacuum; the neutral-atom build where the entire cryogenic stack disappears and the system fits in a standard server rack; the photonic and silicon-spin builds at different stages of supply chain maturity; the cryogenic infrastructure and helium-3 economics that dominate cost and schedule; the HPC integration stack; and the full cost picture from a $2 million entry system to $150 million national laboratory installations. The analysis draws on Applied Quantum's Systems Integration Playbook, the most detailed Western technical reference for assembling quantum computers from modular components.

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