When people talk about scaling quantum systems, they usually focus on qubits — because qubit count and coherence are the most visible measures of performance. But qubits need to be controlled.
Every quantum processor depends on a dense layer of control and readout electronics — the wiring, connectors, microelectronics, and calibration systems that connect room-temperature electronics to devices operating at extremely low temperatures.
If that layer doesn’t scale, the system doesn’t scale.
Through QED-C’s Control and Readout Electronics R&D Program, sponsored by the National Institute of Standards and Technology (NIST), teams from Amphenol RF, XMA, Maybell Quantum Industries, and Rigetti Computing tackled the practical engineering constraints that sit between ambition and scale.
The overwhelming signal from this work is clear: further quantum scaling is an electronics and integration challenge as much as a physics challenge.
Here’s what we’re seeing:
As qubit counts grow, so does the number of control and readout lines required.
Routing those signals from room temperature down to millikelvin environments remains one of the most practical scaling constraints in quantum systems.
This program delivered measurable advances in high-density RF interconnect technology:
These efforts didn’t stop at prototypes. They advanced tooling, assembly methods, and scalable designs suitable for production environments.
The result: a stronger, more capable interconnect supply chain prepared to support higher qubit counts.
Early quantum systems were assembled piece by piece.
Engineers connected long cables to separate signal-conditioning components — devices that reduce signal strength (attenuators), remove unwanted frequencies (filters), and route signals to the right channels.
But assembling many separate pieces adds bulk, variability, and cost. That approach works for prototypes. It doesn’t work for scale.
In this program attenuators were embedded and filtered directly into compact interposer boards and high-density flex architectures. Researchers integrated functions into cohesive subsystems instead of assembling them piece by piece.
Integration delivers:
This work strengthened an emerging product portfolio capable of serving both quantum computing applications and adjacent high-frequency markets.
In fact, some integrated flexline solutions developed through the program are already commercially available, with manufacturing scale-up underway.
Integration improves repeatability, simplifies assembly, and lowers cost per channel — all signals of industry maturation.
At millikelvin temperatures, even small amounts of unintended heating can degrade performance.
For years, engineers had to infer thermal problems indirectly by observing qubit behavior. That made root-cause analysis slow and iterative.
Now teams are embedding thermometry directly onto quantum chips. Instead of guessing, they can measure temperature at the source and correlate it with device performance.
That shift changes the development cycle.
When engineers can measure thermal behavior directly, they can iterate faster on packaging, materials, and layout decisions. They can identify weak points earlier. They can design with thermal awareness from the beginning.
As control and readout systems grow more complex, thermal visibility becomes essential infrastructure.
Cooling a dilution refrigerator takes days. That makes every cooldown valuable.
Engineers improved cryogenic switching and calibration approaches to enable more measurements per cooldown while minimizing additional thermal load. That increases testing throughput and accelerates iteration cycles.
In quantum hardware development, speed matters. The faster teams can design, fabricate, test, and refine control and readout systems, the faster overall system performance improves. High-throughput characterization and automation inside cryogenic environments are no longer optional enhancements. They are competitive necessities.
Perhaps the most important outcome of this program is the strengthening of the control and readout electronics supply chain itself.
Participants focused not only on technical performance but also on:
Several outputs from this program are transitioning from research efforts into product offerings and expanded manufacturing capacity. That shift matters as quantum advantage will emerge when the surrounding infrastructure can support scale reliably, economically, and repeatedly.
Control and readout electronics form the bridge between classical systems and quantum processors. This program strengthened that bridge — with new capabilities, new products, and a more mature supply chain prepared to support the next phase of quantum growth.
Scaling quantum requires scaling the ecosystem. And that ecosystem now has stronger foundations.
Learn more about each project funded by the Control and Readout Electronics R&D program